Apparatus for self-righting a rigid inflatable boat

An apparatus for self-righting a rigid inflatable boat in which said boat has an elongated hull with an elongated rigid bottom and inflatable sidewalls in which an interior measurement between said inflatable sidewalls is at least 52% of its beam, said apparatus comprising:

• an inflatable arch member having first and second leg portions extending upwardly and inwardly substantially from opposite sidewalls of said hull and converging at a central point spaced above said hull;
• said elongated boat hull having a determinable center of gravity and said sidewalls having top, bottom and inner edges and each having an axial centerline;
• said central point being spaced vertically above said top edges a distance equal to at least the sum of one-half the beam of the hull plus a distance equal to a vertical distance at which said center of gravity is located above said sidewalls' bottom edges;
• each said leg portion having an axial centerline which extends upwardly and inwardly substantially in line between the axial centerline of its respective sidewall and a predetermined interim point located at a position which is laterally positioned substantially above the inner edge of said sidewall and vertically above the axial centerline of said sidewall a distance substantially equal to the product of distance Y times (tan X), where:
• Y=one-half the interior measurement between said inflatable sidewalls, and
• X.gtoreq.to 45.degree.;
• said predetermined interim point in no event being higher than said central point;
• said axial centerline of said arch member's leg portion then extending upwardly and inwardly in line to said central point;
• and
• said inflatable arch member being sized to provide a total displacement sufficient to lift said boat and being positioned along said elongated boat hull at a position aft of said center of gravity.

An apparatus for self-righting a rigid inflatable boat in which said boat has an elongated hull with an elongated rigid bottom and inflatable sidewalls in which an interior measurement between said inflatable sidewalls is not more than 52% of its beam, said apparatus comprising:

• an inflatable arch member having first and second leg portions extending upwardly and inwardly substantially from opposite sidewalls of said hull and converging at a central point spaced above said hull;
• said elongated boat hull having a determinable center of gravity and said sidewalls having top, bottom and inner edges and each having an axial centerline;
• said central point being spaced vertically above said top edges a distance equal to at least the sum of one-half the beam of the hull plus a distance equal to a vertical distance at which said center of gravity is located above said sidewalls' bottom edges;
• each said leg portion having an axial centerline which extends upwardly and inwardly substantially in line between the axial centerline of its respective sidewall and a predetermined interim point located at a position which is laterally positioned substantially above the inner edge of said sidewall and vertically above the axial centerline of said sidewall a distance substantially equal to the product of distance Y times (tan X), where:
• Y=one-half the interior measurement between said inflatable sidewalls, and
• X.gtoreq.to 55.degree.;
• said predetermined interim point in no event being higher than said central point;
• said axial centerline of said arch member's leg portion then extending upwardly and inwardly in line to said central point;
• and
• said inflatable arch member being sized to provide a total displacement sufficient to lift said boat and being positioned along said elongated boat hull at a position aft of said center of gravity.