: The Mariner Kayaks web page has the following anecdote. Sea Kayaker Deep
: Trouble chapter 5) "...The afterdeck seemed too high. There had to be
: a solution. He had this flash of insight: "why not lower the back
: deck by filling the kayak up with water?" Having worked so hard to
: bail it out, he now tipped the kayak and filled the cockpit again. The
: context was to point out the irony of bailing out a cockpit only to have
: it filled in again by the rough water that caused the capsize or (as in
: this case) on purpose by the kayaker. But, it made me wonder whether a
: kayak that floats too high would be more difficult to re-enter than one
: that rides a little lower. Is there a float level that will make re-entry
: easier, i.e. using a combination of ballast and floatation?

I would think that it depends on what type of re-entry you're attempting to do. With paddle float re-entries, I douby that it would make that much difference. If you're trying to to a cowboy re-entry, a lower rear deck would probably be a major advantage.

: Does anyone have ideas on a tie down system for gear? The kayak I’m building
: (Expedition Single) will have so much capacity and room that I wonder if
: it can be righted with all that gear rolling about.

The simplest way to secure gear is to use floatation bags to hold it it place and take up any remaining room in the compartment. Use the float bags to hold the gear against the hull, where it will make the boat more stable.

: I read that the coast guard does not approve the use of bulkheads for
: ensuring floatation, but have granted an exception to kayaks and canoes.
: What methods and materials are approved for small craft, and would they
: make the kayak safer?

IIRC, the Coast Guard requires foam floatation. Styrofoam is commonly used, as it's cheap and very buoyant. It could be used in a kayak, but it needs to be encapulatated in some way, since it's not very strong or durable.

: Peter Carter’s web page describes the benefits of an “integrated cockpit” but
: points out the difficulty of designing a complex three-dimensional shape.
: In the post script he describes using foam to fill in the unused space in
: the cockpit. Has anyone tried this approach?

A Sea Sock in a boat without bulkheads is pretty much the same thing, albeit flexible and not permanently attached to the kayak. Building a wooden boat with an integrated cockpit would be very difficult, though not impossible. One thing that I recall from Pete's article is that you can connect the front and rear compartments of the boat with tubes to allow water to seek an even level within the boat. While I understand the logic of this idea, I have a hard time with it, since flooding a sealed compartment to improve safety is a very counterintuitive concept.