As many of you will not have seen the raft close up it is worth describing the construction. It made solely of glass fibre. The area for the terns to nest on is 12ft long by 8ft wide with 1ft sides. This deck is divided into 10 sections by 2in high ridges. Each section has a drainage hole 1in diameter about 1in off the deck. I lengthened these holes almost to the deck but only 1/4in wide when we launched the raft. Supporting this deck are two flotation tanks running the length of the raft, 2ft 6in wide by 1ft 9in deep.