Plastic boat

Claim 1

A BOAT CONSTRUCTION INCLUDING A LOWER SECTION AND AN UPPER DECK, SAID LOWER SECTION AND UPPER DECK HAVING THEIR CONFRONTING EDGES SUPPLIED WITH OUTWARDLY DIRECTED SUBSTANTIALLY HORIZONTAL FLANGES, COMPRESSIBLE GASKET MEANS LOCATED BETWEEN SAID CONFRONTING FLANGES, SUBSTANTIALLY REGULARLY SPACED ATTACHMENT MEANS LOCATED ALONG SAID CONFRONTING FLANGES ATTACHING SID LOWER SECTION AND SAID UPPER DECK FIRMLY AND WATER-TIGHTLY TO EACH OTHER, AT LEAST ONE LONGITUDINAL WELL FORMED CONCAVELY INTO SAID UPPER DECK, LOWER END OF SAID LONGITUDINAL WELL REACHING DOWN ENTIRELY TOWARDS AND CONTACTING THE INNER SURFACE OF SAID LOWER SECTION AT SUBSTANTIAL CENTRAL LOCATION THEREOF, SAID CONTACT BETWEEN SAID LOWER SECTION AND SAID WELL BEING SEALED TOGETHER BY CEMENT MEANS, A PLURALITY OF PARTITIONS LOCATED BETWEEN SAID LOWER SECTION AND SAID UPPER DECK DIVIDING THE SPACE THEREBETWEEN INTO A PLURALITY OF WATERTIGHT COMPARTMENTS, AND AT LEAST ONE AIR VALVE LOCATED IN SAID UPPER DECK IN EACH OF SAID COMPARTMENTS, SAID AIR VALVE SUPPLYING INGRESS AND EGRESS OF AIR TO EACH OF SAID COMPARTMENTS AS REQUIRED, SAID AIR VALVE HAS THE CONFIGURATION OF A GROMMET INSERTED INTO SAID UPPER DECK, SAID AIR VALVE HAVING A SUBSTANTIALLY VERTICAL HOLE LOCATED ENTIRELY THERETHROUGH, COMMUNICATING SAID COMPARTMENT WITH ATMOSPHERE EXTERNALLY OF SAID BOAT CONSTRUCTION, THE INTERNAL END OF SAID HOLE HAVING A SUBSTANTIALLY LARGER DIAMETER THAN THE EXTERNAL END OF SAID HOLE.