US3903823A

US3903823A - Boat recovery system

Info

Publication number: US3903823A
Application number: US462425A
Authority: US
Inventors: John R Kennedy
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-11-17
Filing date: 1974-04-19
Publication date: 1975-09-09
Anticipated expiration: 1992-09-09

Abstract

A boat recovery device is described which consists of a closed slotted drum containing a spool of flexed stainless steel cable or the like with the free end of the cable attached to a flotation unit. The drum is bolted or otherwise fixedly secured to a boat or ship, so that the flotation unit attached to the free end of the cable stays on the surface of the water and as the vessel sinks the cable plays out of the drum. The flotation unit thus serves to mark the location of the sunken vessel and in addition, the drum and mounting are engineered in accordance with the size of the particular vessel so that the cable can be used to raise the sunken vessel to the surface. Various types of flotation units are described which are particularly suited to various applications. One such flotation unit consists of a cylindrical tank having a movable inner piston. The flotation unit is attached to the sunken vessel by the recovery cable and the open bottom end of each tank allows the tank to flood with water as it is lowered. As the tank continues to flood, it sinks of its own weight and slides down along the recovery cable. When the tank has moved down the recovery cable to a position just above the sunken ship, cable locks are actuated to fix the tank in position. Air pressure is fed to the upper portion of the tank so that when the pressure reaches a point greater than the external water pressure, the movable piston moves toward the open end of the tank, forcing the water out and seals the opening. This creates a buoyant uplift force on the recovery cable, thus aiding in raising the sunken vessel.

Description

United States Patent I l I 1 3,903,823

Kennedy l Sept. 9, 1975 l BOAT RECOVERY SYSTEM [76] Inventor: John R. Kennedy, Highway 34. I ABSTRACT Bloomfield A boat recovery device is described which consists of [22] Filed: Apr. [9, 1974 a closed slotted drum containing a spool of flexed stainless steel cable or the like with the free end of the [2H Appl' 462425 cable attached to a flotation unit. The drum is bolted Rented s Appncmion m or otherwise fixedly secured to a boat or ship, so that [63] Continuation of Scr NO m7 NOV '7 the flotation unit attached to the free end of the cable abandoned i i h i stays on the surface of the water and as the vessel sinks the cable plays out of the drum. The flotation 521 U 5. Cl 114/52; 9/9 thus mark the location of the sunken [1 1m. 863B Zl/SZ; 863C 7/08 vessel and in addition the drum and mounting are en- [58] dd of Search v v 9/9 8 1 V5 1 52 gineercd in accordance with the size of the particular H450 vessel so that the cable can be used to raise the sunken vessel to the surface. Various types of flotation [56] References Cited units are described which are particularly suited to t various applications. One such flotation unit consists UNITED SIATES PA1 ENTS of a cylindrical tank having a movable inner piston. lU2,359 4/1870 BCCTS ll4/5Z The mutation unit i attached [0 the sunken vessel y lzaolgo WWW the recovery cable and the open bottom end of each l.272.3U2 7/l9l8 Nylcn ll4/5l A k d h p v l 148 505 x/wzo Ximcnez 114/53 0 5/,927 Grcbowicc 4/53 cred. As the tank continues to flood. it sinks of its own z asx om 12/:943 Wicklow H ll4/2U6 Weight and Slides down s the FCCOVCYY whis- 2 347 690 5/1944 kunncnhgrg H 1 14/5[ When the tank has moved down the recovery cable to 2.421070 2/1969 Clark 9/9 a position just above the sunken Ship, cable locks are .056.978 /1962 Bradley. H actuated to fix the tank in osition. Air ressure is fed P P 3,523 5l4 8/l970 Ftshel i i i 4 l I l/52 to th upper ti f th t k so h h th pres 1654,64) 4/l972 Richardson 9/9 Sure reaches a point greater than the external water FOREIGN PATENTS OR APPLICATIONS pressure, the movable piston moves toward the open n 538 Mlxgg Unitcd Kingdom H W9 end of the tank forcing the water out and seals the ss aux [2/1923 Sweden l |4/52 Opening This Gates a buoyant uplift form On the v covery cable, thus aiding in raising the sunken vessel. Prhrury E'Famiher Trygve 13 Claims, 2l Drawing Figures Assistant b.rumlnerGregory W. O Connor 60 64 66 A iii 67 67 iii 67 i T s 62 68 59 fi I '1,

\II n A; 68 ;'-'.El 7 6 iii i t 69 g I wt 2 v 8 g 1 H F he.... 6/ .i.

PATENTED SEP 9 I975 SHEET 2 [1F 4 [III/III!!! I I PATENTEDSEP 3 903 823 sum u o g 7a SUNKEN Boar BOAT RECOVERY SYSTEM This is a continuation of application Ser. 307,620, filed Nov. I7, 1972, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to vessel recovery devices and more particularly relates to a device for marking the location of and salvaging a sunken vessel such as a boat or Ship.

2. The Prior Art At the present time, there is no known commercially available device which is feasible for the location and recovery of sunken watercraft. While this is a problem of intense concern to owners of small pleasure craft and insurance companies. particularly with the increasingly large number of such craft on our recreational waterways. it is also a severe problem with respect to larger vessels which occasionally sink with attendant immense financial loss.

US. Pat. No. 3,225,368 to Billie W. Allen discloses a device for automatically marking the location of a sunken pleasure craft. However, this device which employs an automatically released marker buoy. is not adapted to the recovery of the vessel and would be entirely unsuitable for salvage operations of larger vessels.

US. Pat. No. 3,341,871 to Oliveau discloses a flotation gear for the recovery of a submerged craft which is relatively complex in its structure employing a pressure sensitive member which is operative in response to a predetermined hydraulic pressure acting thereon when the craft becomes submerged to a predetermined depth, an inflatable form of float with a connecting high pressure gas container and gas release means positioned between the inflatable float and the gas container for filling the float upon its release so that the vessel. particularly drone helicopters, will remain afloat until it may be recovered.

Other prior art patents which disclose vessel recovery systems, generally related to but not as effective or as practical as the present invention are US. Pat. No. I,l76,l96 to Bracy, US. Pat. Nov 2,341,799 to Luby, and US. Pat. No. 1,124,231 to McKenzie.

SUMMARY OF THE INVENTION The primary objective of the present invention is to provide a new and improved system and method for marking the location of sunken vessels both of the pleasure craft and larger types, and aiding in the recovery of such vessels. A feature of the present invention is a flotation device which may be lowered to the sunken vessel along the cable marking the location of the vessel, from the salvage craft.

Briefly, the present invention comprises a closed slot ted drum containing a spool of cable with the free end of the cable attached to a flotation unit. The drum is bolted or otherwise fixedly secured in a desired location on the vessel and more than one such drum and spool of cable may be utilized in various rigging arrangements. If the vessel sinks, the flotation unit attached to the free end of the cable remains on the surface of the water and the cable plays out of the drum as the vessel sinks. The flotation unit on the surface of the water, serves to mark the location of the sunken vessel and may also be employed as a lifesaving device by the passages until help arrives. The cable. drum and mounting are designed for each particular type of vessel on which they are employed, so that the cable can be used to raise the sunken vessel.

A flotation unit. particularly suited to be used with the drum and cable unit of the present invention. comprises a cylindrical tank having a movable inner piston. Its design and construction are such that it can be controlled from the surface recovery vessel and thereby eliminate the need for sending down a deep sea diver. The flotation unit is moved into position on the surface of the water and the recovery cable from the slotted drum is threaded through a cable housing provided on the unit. As the recovery cable is taken up, the flotation unit starts to tip into a vertical position and the open bottom end of each tank allows the tank to flood with the water. The air pressure trapped in the upper por tion of the movable piston is controlled from the recovery ship and as the tank continues to flood. it starts to sink of its own weight and slide down along the recovery cable. A cable lock and air pressure regulator controlled from the recovery ship control the descent of the flotation unit along the recovery cable. When the tank has moved down the recovery cable and is in a position just above the sunken ship. the cable lock is actuated so as to fix the flotation unit to the cable. Air pressure in the upper portion of the tank is increased so that when the pressure reaches an amount greater than the external water pressure, the movable piston starts to move down toward the open end of the tank and the pressure forces the water out the open bottom end of the tank. Once the water has been forced out of the tank, the flotation unit creates a buoyant uplift force on the recovery cable and thus aids in raising the sunken ship.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a side elevational view showing one form of the present invention mounted in the bow of a small pleasure craft;

FIG. 2 is a side elevational view showing the form of the invention of FIG. I mounted in the stern of a small pleasure craft;

FIG. 3 shows the form of the invention of FIGS. I and 2 with a fore and aft rigging;

FIG. 4 is a sectional view taken substantially on the line 4-4 in FIG. 1, looking in the direction of the arrows and specifically illustrating the details of the slotted drum and spool o cable;

FIG. 5 is a sectional view taken substantially on the line 55 of FIG. 4, looking in the direction of the arrows;

FIG. 6 is an exploded perspective of the slotted drum and cable spool assembly;

FIG. 7 is a side elevational view, partly broken away showing another form of the present invention, applied to a larger ship;

FIG. 8 is an enlarged detail of the broken away portion of FIG. 7;

FIG. 9 is a side elcvational view showing another variation in the present invention;

FIG. 10 is a partly perspective view of the manner in which the assembly of FIG. 9 can be used to lower a larger recovery cable to the sunken vessel;

FIG. II is a side elcvational view of a flotation unit particularly suited for use with the present invention;

FIG. 12 is a front elevational view of the flotation unit of FIG. 11;

FIG. 13 is a sectional view taken on the line 13-13 in FIG. 11, looking in the direction of the arrows;

FIG. 14 is a side elevational view of a combination of two of the flotation units shown in the preceding figures;

FIG. 15 is a front elevational view of the flotation unit assembly shown in FIG. 14',

FIG. 16 is an elevational view illustrating the lowering of the flotation unit to the sunken vessel just after the flotation unit has been placed in the water;

FIG. 17 is a further view of the lowering of the flotation unit to the sunken vessel, after it has commenced its descent to the sunken vessel;

FIG. 18 is an enlarged cross-sectional detail taken on the line 18-18 in FIG. 17, looking in the direction of the arrows;

FIG. 19 is a cross-sectional view taken substantially on the line 19-19 in FIG. 18;

FIG. 20 is an enlarged cross-sectional detail taken on the line 20-20 in FIG. 18, looking in the direction of the arrows; and

FIG. 2I is a broken away enlarged detail of the depth markers and guide used in conjunction with the recovery cable illustrated in FIG. 18.

DETAILED DESCRIPTION OF THE INVENTION Referring first to FIGS. 1, 2 and 3, there is illustrated the manner in which the present invention may be mounted in a small boat. As shown in FIG. 1, the drum and cable assembly 12, which will be described in more detail below in connection with FIGS. 4, and 6, may be mounted in the bow of the boat by means of a keel plate 14. The salvage cable 13, which is spooled on the drum of assembly 12. may be threaded through a metal reinforced hole in the upper deck of boat and attached to flotation unit 11, which in the case of a small boat may take the form ofa life preserver. FIG. 2 shows precisely the same type of mounting except that keel plate 14 is now attached at the stern of the boat.

As shown in FIG. 3, a second keel plate 14a may be used to mount an eye bolt in the opposite end of the craft from the drum and cable assembly 12. Attached to eye bolt 15 is a cable bail line 16, having an approximate length of one-half the distance from assembly 12 to eye bolt 15. Attached to the free end of bail line 16 is ring 17 through which salvage cable 13 passes. This arrangement provides two lifting points for the vessel, one fore and one aft, and thus provides double security as well as permitting the craft to be raised in the nearly horizontal position. The recovery of the craft is thereby expedited, once it reaches the surface of the water.

Referring now to FIGS. 4, 5 and 6, there is shown the details of the drum and cable assembly. The assembly comprises an outer housing 21 having cable slot 23 therein and adapted to receive cable spool 24 in its interior. End plates and 25 retain the cable spool in place and are secured thereto by spindle 18,

washers

19 and 26, and lock nut 27. The housing, as mentioned above, is bolted to keel plate 14 by mounting bolts 22.

Before cable 13 is wound on to spool 24, the end of the cable is threaded through hole 23, forming a loop 31, the cable then being fastened together with S- wedge 32. When the unit is assembled, spindle 18 is threaded through washer 19, end plate 20, housing 21, spool 24, loop 31 of the cable 13, end plate 25, washer 26 and nut 27 is then attached. The free end of cable 13 is threaded through slot 23 and loop 29 is formed therein and fastened by means of S-wcdge 30. Quick disconnect snap 28 is attached to loop 29 so that the flotation unit may be easily connected and disconnccted.

In operation, the flotation unit, which in the case of a small pleasure craft with the rigging illustrated in FIGS. 1, 2 and 3, could be a 40-inch diameter life preserver with a smaller preserver on the inside is attached by means of quick disconnect snap 28 to cable 13. As the vessel sinks, the cable plays out and the flotation unit remains on the surface of the water. This not only serves to mark the location of the sunken vessel, but the cable, drum and mounting are engineered to each particular size boat so that the cable can be used to raise the vessel with one of the riggings shown in FIGS. 1, 2 and 3. The amount of cable spooled on the drum is determined by the maximum depth of water in which the craft is expected to be operating and this amount of cable in feet is marked on the flotation unit so as to aid the recovery vessel in determining the depth at which the sunken vessel is located. Thus, when a flotation unit, such as the life preserver 11, shown in FIGS. 1, 2 and 3, is located floating on the surface of the water, the personnel on the recovery vessel will know by examining the unit how much of cable 13 has been wound on the mounting of that particular vessel. By reeling in the cable, which itself may be marked in feet, the salvage crew can determine by subtracting the number of feet reeled in before resistance is encountered, from the number of feet marked on the flotation unit, the depth at which the vessel is located. This will enable the crew to determine the best method of proceeding with the salvage operation and as more fully explained below will enable the crew to properly utilize the unique flotation unit, which forms part of this invention, for assisting in raising the sunken vessel.

Referring now to FIGS. 7 and 8, there is shown one way in which the present invention may be applied to the recovery of a larger vessel, such as a submarine. As shown in FIG. 7, two drum and cable assemblies 12 are utilized in this application, one at each end of the craft. Floats 35 are disposed within water-tight compartments 41 below deck hatch cover 36, which is placed under tension by ejector springs 38. Drum and cable assembly 12 is placed behind water-tight batch cover 39 to provide access thereto and cable guide 34 prevents the cable from becoming snagged. Optionally, float 35 may be provided with antenna 37 and a radio transmitting device to signal the location of the sunken craft.

In operation, when it appears to the captain of the ship that the vessel is about to sink, he may actuate ejector springs 38 by an explosive device or some other well known mechanism. causing hatch cover 36 to open and float 35 to be free to remain at the surface of the water as the vessel sinks. This condition is shown by the broken line portion of FIG. 7.

With reference now to FIGS. 9 and 10, there is shown a means of winding a cable about spool 24 of drum and cable assembly 12 so as to effect the salvage of a heavier vessel, while utilizing a light cable for the drum and cable assembly. As shown in FIG. 9, float 45 may be disposed within an air float chamber, the top of which is flush with deck 50. When the vessel sinks, by one of the methods heretofore described, float 45 will rise to the surface, marking the location of the sunken vessel and cable 46 will play out from drum 24. How

ever, in this case, cable 46 which is a relatively light cable is wound in an endless fashion around spool 24, as shown in FIG. 10. Thus, when it is desired to commence the salvage operation. and a heavier cable 47 is needed to withstand the weight of the sunken vessel, the heavier cable may, as shown in FIG. 10, be attached by means of clamp 48 or the like to cable 46. Cable 46 will then be lifted to the surface around the spool 24 and heavier cable 47 brought around the spool to effect the lifting operation.

Referring now to FIGS. ll, 12 and 13, a flotation unit, generally designated by the reference numeral 60, especially adapted to aid in the recovery of a sunken ship, is illustrated. The design and construction of this unit enable it to be controlled from the surface recovery vessel and thereby eliminate the need for sending down a deep sea diver, As will be more fully apparent from the ensuing description, the purpose of this unit is to provide increased buoyancy to the sunken vessel to aid in raising it. Consequently, by using one or more such units, the size and capacity of the hoisting equipment on the recovery ship can be less than would other wise be the case.

Flotation unit 60 consists basically of a cylindrical tank 61 having an opening 63 at either end and a movable inner piston 62 mounted on piston guides 69. Mounted in either opening 63 are depth gauge and sensing element unit 65 to which are attached the air and control lines which run to the surface vessel. Exter nal eye beam rings 67 are disposed around tank 61 to provide structural support and tank interconnecting brackets 75 are provided for connecting together two flotation units as they are normally used. This arrangement is illustrated below in FIGS. 14 and 15. Air-water seals 68 are provided to effectively provide an air and water seal from one side of piston 62 to the other. Siphon line 64, having valve 66 at one end thereof, is provided for preventing any trapped air from remaining in the tank as the open end of the tank is flooded with water as will more fully appear presently.

Cable guide 70 is provided on one side of tank 61 for permitting the flotation unit to be lowered to the sunken vessel in a manner to be described below. Cable locking mechanisms 71 assist in the lowering of the flo ration unit and securing thereof, and is controlled via two-way cable 73 disposed around pulley 72.

Turning now to FIGS. 14 and 15, it can be seen that two tanks 61 may be joined together by brackets 75 to create one integral unit. Common lines 76 are provided to equalize the pressure in the two tanks so that they operate as one unit, in a manner to be described below.

Turning now to FIGS. 18, 19, and 21, there is illustrated the cable guide and locking mechanism to be used in conjunction with the flotation unit described above. The locking mechanism comprises locking member 77 pivotably mounted at point 81 and secured to the right-hand portion of cable 73, as seen in FIG. 18, by eyelet 78. The right-hand portion of cable 73 is broken at this point and secured by S-wedgcs 82. As can be seen in FIG. 18, when the right-hand portion of cable 73 is pulled upwardly, locking member 77 will pivot in a counterclockwise manner about pivot point 81 and wedge cable 13 against the side of cable guide 70, firmly fixing it in position. On the other hand, when the left-hand portion of cable 73 is raised, locking member 77 will move to the position shown in broken lines, freeing cable 13 from its locked position.

Clamping member 79 is provided at regular intervals, say 10 feet, and serves the purpose of securing and guiding the air hose 74 and locking control cable 73 as well as providing a marking system to indicate to the operator of the recovery vessel the depth to which the flotation unit has sunk. As shown in FIG. 20, clamping member 79 may consist of two identical halves 80 which are secured by nut and bolt assemblies 82.

In operation, two of the tanks 61 are clamped together by brackets in a manner shown in FIGS. 14 and 15 and are, if necessary, towed in a horizontal position behind the recovery vessel with a temporary cap placed over their open ends to prevent them from being flooded until they are ready for use. At this time, the shut-off valve 66 on siphon line 64 is closed to prevent flooding.

When the recovery vessel comes abreast of the float such as that shown in FIGS. 1, 2 and 3, or 7, 8, 9, and 10, note will be taken of the depth at which the vessel is resting, in the manner described above. The flotation unit 60 will then be moved into position on the surface of the water. recovery cable 13, threaded through cable guide 70, the temporary end caps removed from tank 61 and valves 66 opened. As slack in the recovery cable 13 is taken up, the flotation unit starts to tip into a ver tical position, as shown in FIG. 16. The open bottom end of each tank permits the tanks to flood with water and the siphon air line 64 prevent an air bubble from forming in the bottom end of the tanks.

As the tanks continue to flood, the flotation unit 60 tips to a vertical position, as shown in FIG. 17. The air pressure trapped in the upper portion of the movable pistons 62, that is, the right-hand portion of the tank 61, as viewed in FIG. 13, is controlled from the recovcry ship via air line 74. As the tanks 61 continue to flood, they commence sinking of their own weight and slide down along recovery cable 13. The cable lock 71 and regulation of air pressure via line 74 control the descent along the rccovery cable.

When the tanks 61 have moved down the recovery cable 13 and are in a position just above the sunken ship, as determined by the previously ascertained depth of the sunken vessel and the indicia appearing on clamping and marking members 79 described above, the cable locking mechanism 71 is actuated by pulling upwardly on the right-hand portion of cable 73 so that locking member 77 assumes the full line position shown in FIG. 18.

Air pressure in the upper portion of the tanks is then increased via line 74 so that when the air pressure on the righthand side of pistons 62 reaches an amount greater than the external water pressure, pistons 62 start to move down towards the open end of the tank and the water is forced out the open bottom end of each tank. After the water has been forced out of the tanks, the tanks create a buoyant uplift force on the recovery cable and thus aid in raising and sunken ship. Depth gauge sensing mechanism 65, which may be operated in either an automatic or a manual way, insures that the air pressure inside of the tanks will be reduced so that the tanks will not rupture due to excess air pressure as the tanks near the surface of the water.

While specific embodiments of the present invention have been described, it will be realized that various modifications may be made therein which will be readily apparent to those skilled in the art. It is therefore, intended. that the scope of this invention be defined only by the claims appended herebelow.

1 claim:

1. Apparatus for marking the location of a sunken vessel and for recovering said vessel. comprising in combination:

a. spool means for winding a cable thereon;

b. means for rigidly securing said spool means to said vessel;

c. float means attached to said cable for marking the location of said vessel after it has sunk, so that said vessel can be raised by means of said cable;

d. flotation means comprising a cylinder having an opening in one end thereof for admitting water thereto so that said flotation means may sink to the vicinity of said sunken vessel. a piston slidably mounted in the interior of the cylinder, air hose means having depth marking indicia along its length controlled from a recovery vessel for admitting air to said cylinder on the side of the piston opposite said opening in the cylinder for replacing said water with air so that said flotation means will create a buoyant effect during the recovery procedure;

c. said flotation means further comprising means engaging said cable so that said flotation means may be lowered to said sunken vessel;

f. said cylinder having cable guide means 5 r receiving said cable from said spool means;

g. cable lock means for locking said flotation means to said cable at any desired point. including actuating means controlled from the recovery vessel, comprising a second cable linked with said cable lock means and in communication with the recov ery vessel; and

h. means for securing said air hose to said second cable.

2. The apparatus set forth in claim 1, further including housing means for said spool means, said housing means comprising a slot through which said cable passes.

3. The apparatus set forth in claim 2, wherein said housing means is bolted to the keel of said vessel.

4. The apparatus set forth in claim 3, wherein said float means comprises indicia indicating the number of feet of cable wound on said spool means and said number of feet is determined by the maximum depth of water in which said vessel is expected to travel.

5. Apparatus for recovering a sunken vessel. comprising in combination:

a. cable means secured to said vessel; and

b. cylindrical flotation means for assisting in raising said sunken vessel, said flotation means comprising:

i. means engaging said cable means so that said flo tation means may be lowered to said sunken vessel;

ii. an opening in one end of said flotation means for admitting water thereto to permit said flotation means to sink to the vicinity of said sunken vessel;

iii. piston means slidably mounted in the interior of said cylinder for replacing said water with air to create a buoyant effect during the recovery procedure; and

iv. conduit means selectively connected to atmospheric pressure for removing trapped air from the end of said cylinder having said opening as water is admitted thereto.

6. The apparatus set forth in claim 5, wherein said cylinder comprises cable guide means for receiving said cable.

7. The apparatus set forth in claim 5, wherein said means for replacing said water comprises air hose means controlled from a recovery vessel for admitting air to said cylinder on the side of said piston opposite to said opening in the cylinder.

8. The apparatus set forth in claim 6, further including cable lock means cooperating with said cable guide means for locking said flotation means to said cable at any desired point.

9. The apparatus set forth in claim 8, wherein said cable lock means comprises actuating means controlled from the recovery vesselv 10. The apparatus set fourth in claim 9, wherein said actuating means comprises a second cable linked with said cable lock means and in communication with the recovery vessel.

1 l. The apparatus set forth in claim 10, wherein said air hose means comprises depth marking indicia along its length and means for securing said air hose to said second cable.

12. The apparatus set forth in claim 5 further including valve means for selectively connecting said conduit means to atmospheric pressure.

13. The apparatus set forth in claim 5, wherein said conduit means comprises a flexible hose.

Claims

1. Apparatus for marking the location of a sunken vessel and for recovering said vessel, comprising in combination: a. spool means for winding a cable thereon; b. means for rigidly securing said spool means to said vessel; c. float means attached to said cable for marking the location of said vessel after it has sunk, so that said vessel can be raised by means of said cable; d. flotation means comprising a cylinder having an opening in one end thereof for admitting water thereto so that said flotation means may sink to the vicinity of said sunken vessel, a piston slidably mounted in the interior of the cylinder, air hose means having depth marking indicia along its length controlled from a recovery vessel for admitting air to said cylinder on the side of the piston opposite said opening in the cylinder for replacing said water with air so that said flotation means will create a buoyant effect during the recovery procedure; e. said flotation means further comprising means engaginG said cable so that said flotation means may be lowered to said sunken vessel; f. said cylinder having cable guide means for receiving said cable from said spool means; g. cable lock means for locking said flotation means to said cable at any desired point, including actuating means controlled from the recovery vessel, comprising a second cable linked with said cable lock means and in communication with the recovery vessel; and h. means for securing said air hose to said second cable.

5. Apparatus for recovering a sunken vessel, comprising in combination: a. cable means secured to said vessel; and b. cylindrical flotation means for assisting in raising said sunken vessel, said flotation means comprising: i. means engaging said cable means so that said flotation means may be lowered to said sunken vessel; ii. an opening in one end of said flotation means for admitting water thereto to permit said flotation means to sink to the vicinity of said sunken vessel; iii. piston means slidably mounted in the interior of said cylinder for replacing said water with air to create a buoyant effect during the recovery procedure; and iv. conduit means selectively connected to atmospheric pressure for removing trapped air from the end of said cylinder having said opening as water is admitted thereto.

9. The apparatus set forth in claim 8, wherein said cable lock means comprises actuating means controlled from the recovery vessel.

10. The apparatus set fourth in claim 9, wherein said actuating means comprises a second cable linked with said cable lock means and in communication with the recovery vessel.

11. The apparatus set forth in claim 10, wherein said air hose means comprises depth marking indicia along its length and means for securing said air hose to said second cable.