Ringboat

Claim 1

A VESSEL HAVING A FLEXIBLE LOWER PART THAT FLOATS IN WATER AND AN UPPER PART THAT HAS LIGHTER-THAN-AIR COMPONENTS, COMPRISING: A PLURALITY OF SUBSTANTIALLY AIRTIGHT, INFLATABLE RECEPTACLES, HAVING WALLS OF FLEXIBLE MATERIAL CAPABLE OF REPEATEDLY YIELDING UNDER SEVERE SHOCK AND RETURNING SUBSTANTIALLY TO THEIR FORMER CONFIGURATIONS, SAID RECEPTACLES FORMING STRUCTURAL, STRENGTH-PROVIDING FRAMEWORK FOR SAID UPPER AND LOWER PARTS, AT LEAST SOME OF THE RECEPTACLES BEING CONSTRUCTED AND ARRANGED TO PROVIDE A USEFUL-LOAD CONTAINING SPACE; COMPRESSED GAS IN SAID RECEPTACLES HAVING A PRESSURE GREATER THAN THAT OF THE ATMOSPHERE; MEANS HOLDING SAID RECEPTACLES TOGETHER; AND HOLLOW, CAVITY-CONTAINING HERMETICALLY-SEALED, LIGHTER-THAN-AIR UNITS FLOATING SUPPORTED IN THE COMPRESSED GAS WITHIN AT LEAST SOME OF SAID RECEPTACLES OF SAID UPPER PART, EACH OF SAID UNITS HAVING A CLEARANCE BENEATH ITS UNDER SIDE, RELATIVE TO THE FLEXIBLE WALLS OF ONE OF SAID RECEPTACLES AND BEING SMALL ENOUGH TO PERMIT THE UNIT TO MOVE INTO SAID CLEARANCE WHEN THE RECEPTACLE FLEXES AT A POINT OF CONTACT BETWEEN IT AND SAID UNIT, SAID UNITS HAVING THIN WALLS OF MATERIAL THAT IS IMPERMEABLE TO GAS, AND HAVING SUBSTANTIAL VOLUME AND LIFTING POWER ABOVE THE VESSEL''S CENTER OF GRAVITY.