Reality outpasses fiction as usual. I've read from another boatbuilding site that some mason built a boat's hull with concrete, then made the bulkheads of adobe, then added flower-stands on deck to make his boat look nicer!
The boat sank at dock even before starting her maiden voyage.
I was luckier with my plywood zeppelin!
Season's greetings!

: They have been made from concrete, so why not from adobe? You would need to
: make a boat that had a displacement that would be somewhat greater than
: for a wood boat, but that is not too difficult. An 18 foot long and 24
: inch wide kayak should have a maximum displacement around 600 to 650
: pounds. Depending on hull cross section and sidewall height this might
: even be greater. If the boat weighs about 300 to 350 pounds then it could
: still carry a 200 pound paddler and have some freeboard.

: The major problem with adobe as opposed to concrete is that adobe can be
: softened by constant exposure to water. You would need to solve this by
: coating the adobe boat with a suitable waterproof coating. A few layers of
: epoxy resin might do, or you might look at using some of the waterborne
: urethanes. You want the adobe to be very dry before you coat it, and it
: will probably soak up a lot of coating. For economy, you might try
: polyester resin.

: Consider making many bulkheads and sealed, watertight, compartments in the
: interior. The added materials will certainly add weight to the boat, and
: reduce the interior storage space, but you'll probably need the cross
: bracing this type of construction supplies as adobe is not real strong.
: Any additional reinforcement that could be embedded in the adobe would
: help with the strength: wood lath, rebar, chicken wire, etc. Even straw
: would be a useful reinforcement.

: Best of luck, and be sure to bring along enough PFDs on or first launch --
: just in case the boat dissolves and leaves you without the option of a
: second launch.

: Did Santa by any chance leave a bottle of something in your xmas stocking?
: Just wondering where you got the idea for such a boat.

: PGJ