In some defense of old Lofty, the SAS tins have a rubber gasket and if taped tightly closed they stay fairly dry.

If you recall in your other post I had recommended a plastic waterproof case, not a Pelican but a Witz because it is lighter than the Pelican. I bought some various size Pelican cases for a planned two week trip to the jungles of Borneo, they are great but heavy and bulky for a pack, at least. The cases never were packed up and the Borneo trip was not to be afterall.

Good luck with the revised kit, I am sure a canoe/kayak kit for a PFD will be much more secure in a Pelican.
Looks like a fun trip in the pics! Cheers.