US3124094A - Stabilizing arrangement for power boats - Google Patents

Stabilizing arrangement for power boats Download PDF

Info

Publication number
US3124094A
US3124094A US3124094DA US3124094A US 3124094 A US3124094 A US 3124094A US 3124094D A US3124094D A US 3124094DA US 3124094 A US3124094 A US 3124094A
Authority
US
United States
Prior art keywords
fin
boat
axes
axis
support
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Publication date
Application granted granted Critical
Publication of US3124094A publication Critical patent/US3124094A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B63SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63BSHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B39/00Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude
    • B63B39/06Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by using foils acting on ambient water
    • B63B39/061Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by using foils acting on ambient water by using trimflaps, i.e. flaps mounted on the rear of a boat, e.g. speed boat

Definitions

  • the main object of the invention is to provide a device which may be used for stabilizing a power boat.
  • the device comprises at least one stabilizing fin which is positioned in a sloping relation to the water level surface and adapted to pivot about an axis substantially parallel to the longitudinal center axis of the ship.
  • the said sloping fin is also pivotable about an axis extending transversely of the normal direction of boat movement.
  • the sloping fin has on its downwardly directed face a longitudinal vertical fin or rib.
  • Such a vertical fin may also be mounted on the upwardly directed face of the sloping fin.
  • the steering device is preferably mounted on the stern portion or the transom of the boat so that it is entirely located behind the boat hull.
  • the device may be positioned under the after portion of the vessel and the control and driving connections can be placed in a suitable well in the bottom of the ship.
  • a stabilizing arrangement should preferably comprise two stabilizing attachments, one on each side of the longitudinal axis of the vessel.
  • the sloping fin can be pivoted about two axes substantially crossing one another at a right angle, but not necessarily lying in one and the same plane.
  • the stern end of the boat has a tendency to be pressed down into the water when the speed is increased, particularly with a heavy load, or when the load is not distributed correctly.
  • a suitable adjustment of the sloping angle of the fins will cause the stern of the boat to be lifted from the water so that the boat will be able to plane more easily.
  • the stern end may also be lifted to some distance over the water surface.
  • the sloping fins are pivoted about the horizontal longitudinal axis in one or the other direction, the boat will move in an are without causing the side of the stern nearer the center of the arc to be pressed down into the water. This is advantageous, as a rather small boat may be used in a rough sea and yet move at a high travelling 'speed.
  • FIG. 1 is a vertical longitudinal section of a boat stern portion or transom equipped with a stabilizing attachment of the invention
  • FIG. 1a is a side view of a holding bracket for the fin lifting mechanism of the attachment of FIG. 1,
  • FIG. 2 is a rear elevational view of the stabilizing and steering attachment
  • FIG. 3 shows the stern of the boat provided with a twin steering arrangement of the invention.
  • a support plate 3 of metallic or plastic material is fixed by means of screws 2 on the transom 1 of a boat and a normally horizontal pivot 4 with its pivoting axis 4a extending in the longitudinal direction of the boat is supported on the lower portion of the plate 3.
  • a guiding plate 5 having a hub 6 is pivotally fixed on the pivot 4.
  • the hub 6 engages the pivot 4.
  • the hub is provided with a grease nipple 6a.
  • the lower edge 7 of the plate 5 extends substantially hori- 3,124,094 Patented Mar. 10, 1964 "ice zontally, and the upper portion 8 of the plate 5 has a semi-circular guiding slot 9 for a guiding pin 10 one end of which is firmly threaded into the supporting plate 3.
  • the outer end of the pin 10 has threads carrying a nut 11.
  • a helical spring 12 pressing with one end against a washer 13 engaging the guiding plate 5 can be compressed more or less by means of the nut 11 and an intermediate washer 14 so that the friction force between the supporting plate 3 and the guiding plate 5 can be adjusted.
  • the guiding plate 5 carries an upwardly elongated lever arm 15 reinforced with a rib 15a, and the lever arm 15 has in its upper end a hole 16 for connection with the steering wheel or handle of the boat.
  • the front edge of a plate shaped fin 18 is hingedly connected by a pin 17a with the lower edge 7 of the guiding plate 5.
  • the front of the fin 13 is about as wide as the guiding plate but the fin width increases gradually rearwardly.
  • the pivot connection can comprise one or more hinges 17.
  • the fin 18 is pivoted about the pin 17a for changing of the angle between the fin and the water surface. If desired, the plate 13 may be lifted entirely from the water, for instance when the boat shall be transported on a trailer or the like.
  • the underside of the fin 18 is provided with a longitudinal vertical fin 19 extending along the center line thereof.
  • Means for pivoting the fin 18 about the axis of the pin 17, comprise a bracket Zil fixed on the upper portion of the lever arm 15 and having two substantially horizontal arms 21 (FIG. In) each provided with a horizontal slot 22.
  • a sleeve 23 having a threaded bore carries two lateral bolts 24 guided in the slots 22 for movement against the action of two helical springs 27 located between the sleeve walls and abutments 29 arranged between the bracket arms 21.
  • the springs are guided by pins 28 fixed on the sleeve and extending through holes in the abutments 29.
  • the lower end of a two-piece linking rod 33, 33a is hinged to a bracket 25 on the fin 18, and the upper rod portion 33 is provided with threads 26 cooperating with the threads in the bore of the sleeve 23.
  • the top of the rod 33 is provided with a turning handle 27 by means of which the slope of the fin 18 may be adjusted.
  • the lower portion 33a of the adjusting rod carries a connector 34 rotatably engaging the upper portion 33 of the rod.
  • two identical stabilizing attachments are located on opposite sides of the longitudinal center plane of the boat.
  • the upper ends of the lever arms 15 are linked by means of a bar 30, as shown in FIG. 3.
  • the bar 3 3 is made of two pieces so that its length can be adjusted.
  • the midportion of the bar has an eyelet 31 (FIG. 3) for a wire 32 or the like which is connected with the rudder tiller or steering wheel.
  • the bar 30' causes the two devices to carry out identical pivoting motions about the axes 4a.
  • a stabilizer attachment for a boat comprising, in combination:
  • pivot means interposed between said support and said fin for pivotal movement of said fin about two axes toward and away from a normal position in which the faces of said fin are directed upward and downward respectively, when said support is in said predetermined position, said axes being perpendicular to each other and normally horizontal;
  • pivot means include a pivot member pivotally secured to said support for movement about the other one of said axes, said fin being pivotally atached to said pivot member for movement about said one axis.
  • abutment means include two abutment members, one abutment member being formed with an aperture and the other abutment member being arranged for movement in said aperture, one of said abutment members being secured to said support against movement about said other axis, and the other abutment member being connected to said fin for pivotal movement therewith about said other axis.
  • said means for pivoting said fin include link means for connecting said fin to a portion of said boat upwardly spaced from said pivot means, said link means having two portions threadedly engaged for varying the length of said link means.
  • a stabilized boat comprising, in combination:
  • pivot means interposed between said hull and said fin for pivotal movement of said fin about two normally horizontal axes perpendicular to each other toward and away from a position in which the faces of said fin are directed upward and downward respectively, one of said axes being transverse of the normal direction of movement of said boat;
  • pivot means include a pivot pin attached to said hull and having a normally horizontal axis extending in said normal direction of boat movement, a hub member engaging said pivot pin for movement about the axis thereof, said fin being hingedly secured to said hub member for movement relative thereto about a normally horizontal axis transverse of said normal direction of boat movement.
  • said abutment means include a guide plate on said hub member, said guide plate being formed with an aperture, and an abutment member fastened to said hull and engaging said aperture.
  • pivoting means include link means interposed between said fin and a portion of said hull normally upwardly spaced from said pivot means, said link means including two link members threadedly connected for varying the length of said link means when said link members are rotated relative to each other.
  • a stabilized boat comprising, in combination:
  • pivot means interposed between said hull and each fin for pivotal movement of said fin about two normally horizontal pivoting axes perpendicular to each other toward and away from a position in which the faces of said fin are directed upward and down- Ward respectively, one of said pivoting axes being transverse of said longitudinal axis;
  • pivoting means for pivoting each of said fins about one of said pivoting axes thereof.

Description

March 10, 1964 K. BRATEN 3,124,094
STABILIZING ARRANGEMENT FOR POWER BOATS Filed June 29, 1962 I 2 Sheets-She et 1 FIG/a. FIG].
luvnvrot X415 16644;?-
March 10, 1964 K. BRATEN 3,124,094
STABILIZING ARRANGEMENT FOR POWER BOATS Filed June 29, 1962 2 Sheets-Sheet 2 F/GZ.
IN vl/ z z z M United States Patent 3,124,094 STABILIZING ARRANGEMENT FOR POWER BGATS Kjell Britten, Kr. Anhertsvei 32, Rea, Norway Filed June 29, 1962, Ser. No. 206,315 13 Claims. (Cl. 114-665) This invention relates to a stabilizing device for boats.
The main object of the invention is to provide a device which may be used for stabilizing a power boat.
In accordance with the invention the device comprises at least one stabilizing fin which is positioned in a sloping relation to the water level surface and adapted to pivot about an axis substantially parallel to the longitudinal center axis of the ship.
In accordance with another feature of the invention the said sloping fin is also pivotable about an axis extending transversely of the normal direction of boat movement. The sloping fin has on its downwardly directed face a longitudinal vertical fin or rib. Such a vertical fin may also be mounted on the upwardly directed face of the sloping fin.
In smaller boats the steering device is preferably mounted on the stern portion or the transom of the boat so that it is entirely located behind the boat hull.
In greater boats the device may be positioned under the after portion of the vessel and the control and driving connections can be placed in a suitable well in the bottom of the ship. A stabilizing arrangement should preferably comprise two stabilizing attachments, one on each side of the longitudinal axis of the vessel.
From the above it appears that the sloping fin can be pivoted about two axes substantially crossing one another at a right angle, but not necessarily lying in one and the same plane.
It is a disadvantage of small power boats that the stern end of the boat has a tendency to be pressed down into the water when the speed is increased, particularly with a heavy load, or when the load is not distributed correctly. A suitable adjustment of the sloping angle of the fins will cause the stern of the boat to be lifted from the water so that the boat will be able to plane more easily. The stern end may also be lifted to some distance over the water surface. When the sloping fins are pivoted about the horizontal longitudinal axis in one or the other direction, the boat will move in an are without causing the side of the stern nearer the center of the arc to be pressed down into the water. This is advantageous, as a rather small boat may be used in a rough sea and yet move at a high travelling 'speed.
The above and other objects and advantages of the invention will be more fully appreciated from the following description when taken in connection with the accompanying drawings, in which:
FIG. 1 is a vertical longitudinal section of a boat stern portion or transom equipped with a stabilizing attachment of the invention,
FIG. 1a is a side view of a holding bracket for the fin lifting mechanism of the attachment of FIG. 1,
FIG. 2 is a rear elevational view of the stabilizing and steering attachment, and
FIG. 3 shows the stern of the boat provided with a twin steering arrangement of the invention.
Referring to FIG. 1, a support plate 3 of metallic or plastic material is fixed by means of screws 2 on the transom 1 of a boat and a normally horizontal pivot 4 with its pivoting axis 4a extending in the longitudinal direction of the boat is supported on the lower portion of the plate 3. A guiding plate 5 having a hub 6 is pivotally fixed on the pivot 4. The hub 6 engages the pivot 4. The hub is provided with a grease nipple 6a. The lower edge 7 of the plate 5 extends substantially hori- 3,124,094 Patented Mar. 10, 1964 "ice zontally, and the upper portion 8 of the plate 5 has a semi-circular guiding slot 9 for a guiding pin 10 one end of which is firmly threaded into the supporting plate 3.
The outer end of the pin 10 has threads carrying a nut 11. A helical spring 12 pressing with one end against a washer 13 engaging the guiding plate 5 can be compressed more or less by means of the nut 11 and an intermediate washer 14 so that the friction force between the supporting plate 3 and the guiding plate 5 can be adjusted. The guiding plate 5 carries an upwardly elongated lever arm 15 reinforced with a rib 15a, and the lever arm 15 has in its upper end a hole 16 for connection with the steering wheel or handle of the boat.
As shown in FIGS. 1 and 2, the front edge of a plate shaped fin 18 is hingedly connected by a pin 17a with the lower edge 7 of the guiding plate 5. In the normal driving position the fin 18 is downwardly and rearwardly. The front of the fin 13 is about as wide as the guiding plate but the fin width increases gradually rearwardly. The pivot connection can comprise one or more hinges 17. The fin 18 is pivoted about the pin 17a for changing of the angle between the fin and the water surface. If desired, the plate 13 may be lifted entirely from the water, for instance when the boat shall be transported on a trailer or the like. The underside of the fin 18 is provided with a longitudinal vertical fin 19 extending along the center line thereof.
Means for pivoting the fin 18 about the axis of the pin 17, comprise a bracket Zil fixed on the upper portion of the lever arm 15 and having two substantially horizontal arms 21 (FIG. In) each provided with a horizontal slot 22. A sleeve 23 having a threaded bore carries two lateral bolts 24 guided in the slots 22 for movement against the action of two helical springs 27 located between the sleeve walls and abutments 29 arranged between the bracket arms 21. The springs are guided by pins 28 fixed on the sleeve and extending through holes in the abutments 29. The lower end of a two- piece linking rod 33, 33a is hinged to a bracket 25 on the fin 18, and the upper rod portion 33 is provided with threads 26 cooperating with the threads in the bore of the sleeve 23. The top of the rod 33 is provided with a turning handle 27 by means of which the slope of the fin 18 may be adjusted. The lower portion 33a of the adjusting rod carries a connector 34 rotatably engaging the upper portion 33 of the rod.
When the boat travels straight forward or along a curve, it is stabilized by pivoting of the guiding plate 5 with the fin 18 about the horizontal pivot 4 by means of the lever arm 15.
In a preferred embodiment of the invention two identical stabilizing attachments are located on opposite sides of the longitudinal center plane of the boat.
The upper ends of the lever arms 15 are linked by means of a bar 30, as shown in FIG. 3. The bar 3 3 is made of two pieces so that its length can be adjusted. The midportion of the bar has an eyelet 31 (FIG. 3) for a wire 32 or the like which is connected with the rudder tiller or steering wheel. The bar 30' causes the two devices to carry out identical pivoting motions about the axes 4a.
It should be understood that the invention is not limited to the embodiments shown in the drawings and described above as various changes may of course be made without departing from the scope of the invention.
What I claim is:
l. A stabilizer attachment for a boat comprising, in combination:
(a) a support;
(12) attaching means for attaching said support. to a boat in a predetermined position;
() a plate shaped fin having two opposite major faces;
(d) pivot means interposed between said support and said fin for pivotal movement of said fin about two axes toward and away from a normal position in which the faces of said fin are directed upward and downward respectively, when said support is in said predetermined position, said axes being perpendicular to each other and normally horizontal; and
(e) means for pivoting said fin about one of said axes.
2. An attachment as set forth in claim 1, wherein said pivot means include a pivot member pivotally secured to said support for movement about the other one of said axes, said fin being pivotally atached to said pivot member for movement about said one axis.
3. An attachment as set forth in claim 2, wherein said other axis extends longitudinally of said boat when said support is attached to said boat by said attaching means in said predetermined position.
4. An attachment as set forth in claim 1, further comprising a rib member on the normally downwardly directed face of said fin, said rib member being elongated transversely of said one axis.
5. An attachment as set forth in claim 1, further comprising abutment means for limiting pivotal movement of said fin about said other axis.
6. An attachment as set forth in claim 5, wherein said abutment means include two abutment members, one abutment member being formed with an aperture and the other abutment member being arranged for movement in said aperture, one of said abutment members being secured to said support against movement about said other axis, and the other abutment member being connected to said fin for pivotal movement therewith about said other axis.
7. An attachment as set forth in claim 1, wherein said means for pivoting said fin include link means for connecting said fin to a portion of said boat upwardly spaced from said pivot means, said link means having two portions threadedly engaged for varying the length of said link means.
8. A stabilized boat comprising, in combination:
(a) a hull;
(b) a plate shaped fin having two opposite major faces;
(c) pivot means interposed between said hull and said fin for pivotal movement of said fin about two normally horizontal axes perpendicular to each other toward and away from a position in which the faces of said fin are directed upward and downward respectively, one of said axes being transverse of the normal direction of movement of said boat; and
(d) pivoting means for pivoting said fin about said one axis.
9. A boat as set forth in claim 8, wherein said pivot means include a pivot pin attached to said hull and having a normally horizontal axis extending in said normal direction of boat movement, a hub member engaging said pivot pin for movement about the axis thereof, said fin being hingedly secured to said hub member for movement relative thereto about a normally horizontal axis transverse of said normal direction of boat movement.
10. A boat as set forth in claim 9, further comprising cooperating abutment means on said hull and on said hub member for limiting pivotal movement of said hub memher about the axis of said pivot pin.
11. A boat as set forth in claim 10, wherein said abutment means include a guide plate on said hub member, said guide plate being formed with an aperture, and an abutment member fastened to said hull and engaging said aperture.
12. A boat as set forth in claim 8, wherein said pivoting means include link means interposed between said fin and a portion of said hull normally upwardly spaced from said pivot means, said link means including two link members threadedly connected for varying the length of said link means when said link members are rotated relative to each other.
13. A stabilized boat comprising, in combination:
(a) a hull having a longitudinal axis;
(b) two plate shaped fins arranged on opposite sides of said axis, each fin having two opposite major faces;
(c) pivot means interposed between said hull and each fin for pivotal movement of said fin about two normally horizontal pivoting axes perpendicular to each other toward and away from a position in which the faces of said fin are directed upward and down- Ward respectively, one of said pivoting axes being transverse of said longitudinal axis; and
(d) pivoting means for pivoting each of said fins about one of said pivoting axes thereof.
References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS Great Britain of 1908 France July 6, 1925

Claims (1)

1. A STABILIZER ATTACHMENT FOR A BOAT COMPRISING, IN COMBINATION: (A) A SUPPORT; (B) ATTACHING MEANS FOR ATTACHING SAID SUPPORT TO A BOAT IN A PREDETERMINED POSITION; (C) A PLATE SHAPED FIN HAVING TWO OPPOSITE MAJOR FACES; (D) PIVOT MEANS INTERPOSED BETWEEN SAID SUPPORT AND SAID FIN FOR PIVOTAL MOVEMENT OF SAID FIN ABOUT TWO AXES TOWARD AND AWAY FROM A NORMAL POSITION IN WHICH THE FACES OF SAID FIN ARE DIRECTED UPWARD AND DOWNWARD RESPECTIVELY, WHEN SAID SUPPORT IS IN SAID PREDETERMINED POSITION, SAID AXES BEING PERPENDICULAR TO EACH OTHER AND NORMALLY HORIZONTAL; AND (E) MEANS FOR PIVOTING SAID FIN ABOUT ONE OF SAID AXES.
US3124094D Stabilizing arrangement for power boats Expired - Lifetime US3124094A (en)

Publications (1)

Publication Number Publication Date
US3124094A true US3124094A (en) 1964-03-10

Family

ID=3453564

Family Applications (1)

Application Number Title Priority Date Filing Date
US3124094D Expired - Lifetime US3124094A (en) Stabilizing arrangement for power boats

Country Status (1)

Country Link
US (1) US3124094A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3200782A (en) * 1964-11-06 1965-08-17 Samuel L Walden Power boat attachment
US3602178A (en) * 1970-03-27 1971-08-31 William B White Boat planing and brake apparatus
US3628484A (en) * 1970-03-14 1971-12-21 Philip M Banner Trim tab means for marine craft
US4323027A (en) * 1980-06-23 1982-04-06 Schermerhorn William H Trim tab for power boat

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB190808472A (en) * 1908-04-16 1909-04-16 John Fisher Le Page Improvements in Vessels or Boats for Navigating Water
US1529036A (en) * 1921-05-09 1925-03-10 Clarence F Richey Rudder arrangement for surface boats
FR594911A (en) * 1924-12-14 1925-09-23 Steering device for river and sea vessels
US1600419A (en) * 1925-01-02 1926-09-21 Mainelli Roberto Rudder with horizontal axis
US1800408A (en) * 1928-01-11 1931-04-14 Sperry Gyroscope Co Inc Roll and pitch reducing device for ships
US1805131A (en) * 1928-06-08 1931-05-12 Jacob Ruppert Schalk Boat
US2329220A (en) * 1939-07-12 1943-09-14 Burke Rummler Sailing and sailing gear
US2864330A (en) * 1955-11-23 1958-12-16 Park Jones Braking or trolling attachment for boats
US2914019A (en) * 1954-09-27 1959-11-24 Gewin William Miller Trolling device for reducing the effectiveness of a propeller
US2994290A (en) * 1961-08-01 Retractible drag device for boats
US3026839A (en) * 1960-08-22 1962-03-27 Clifford V Fridge Boats
US3046928A (en) * 1959-09-28 1962-07-31 Sea Trim Corp Boat trimming stabilizer

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2994290A (en) * 1961-08-01 Retractible drag device for boats
GB190808472A (en) * 1908-04-16 1909-04-16 John Fisher Le Page Improvements in Vessels or Boats for Navigating Water
US1529036A (en) * 1921-05-09 1925-03-10 Clarence F Richey Rudder arrangement for surface boats
FR594911A (en) * 1924-12-14 1925-09-23 Steering device for river and sea vessels
US1600419A (en) * 1925-01-02 1926-09-21 Mainelli Roberto Rudder with horizontal axis
US1800408A (en) * 1928-01-11 1931-04-14 Sperry Gyroscope Co Inc Roll and pitch reducing device for ships
US1805131A (en) * 1928-06-08 1931-05-12 Jacob Ruppert Schalk Boat
US2329220A (en) * 1939-07-12 1943-09-14 Burke Rummler Sailing and sailing gear
US2914019A (en) * 1954-09-27 1959-11-24 Gewin William Miller Trolling device for reducing the effectiveness of a propeller
US2864330A (en) * 1955-11-23 1958-12-16 Park Jones Braking or trolling attachment for boats
US3046928A (en) * 1959-09-28 1962-07-31 Sea Trim Corp Boat trimming stabilizer
US3026839A (en) * 1960-08-22 1962-03-27 Clifford V Fridge Boats

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3200782A (en) * 1964-11-06 1965-08-17 Samuel L Walden Power boat attachment
US3628484A (en) * 1970-03-14 1971-12-21 Philip M Banner Trim tab means for marine craft
US3602178A (en) * 1970-03-27 1971-08-31 William B White Boat planing and brake apparatus
US4323027A (en) * 1980-06-23 1982-04-06 Schermerhorn William H Trim tab for power boat

Similar Documents

Publication Publication Date Title
US3092857A (en) Water sled
US3112725A (en) Sailboat
US2910708A (en) Water sled
US4811674A (en) Foil arrangement for water-borne craft
US4154417A (en) Adjustable mount for trolling motor
US2238464A (en) Convertible sailing vessel
US2948251A (en) Diving plane
US2955559A (en) Hydrofoil watercraft
US3150632A (en) Self-propelled water craft
US4349340A (en) Man-propelled hydrofoil boat
US3628484A (en) Trim tab means for marine craft
US3124094A (en) Stabilizing arrangement for power boats
US3565030A (en) Adjustable stabilizer for boats
US2998791A (en) Control apparatus for water craft
US3026121A (en) Midget ice boat
NO167846B (en) SKI BINDING FOR FIXED TENSION OF A BOOT FOR A LONG RANGE SKI.
US3041994A (en) Kit sail for boats
US3016864A (en) Boat construction
US3371642A (en) Trim control device for boats
US3703877A (en) Water scooter
US3370561A (en) Trim and heeling board device for boats
US3099239A (en) Retractable hydrofoil system for water craft
US4014283A (en) Watercraft, particularly for watersports
US2720180A (en) Hydrofoil system for water craft
US3469552A (en) Hawser steering anti-yawing and safety mechanism for towed barges and the like