Perhaps get it the hulls modified to accept screw-on lids with o-rings. Then you can shove gear straight in. You may then have to consider bulkheads to allow some floatation should one 'chamber' be perforated.
About 15 years ago, AG had a small article about two guys who sailed from Cairns or somewhere south to TI, where they sold it. They had slept on the trampoline due to croc concerns (I recall because one the guys was part of the first successful team to put Australians on the summit of Mt Everest in 1984, either Geof Bartram or Andy Henderson). Jesse Martin and his father sailed a cat along the remote Cape York coast I think, mentioned in his book about Lionheart.