: My goal is to design a craft that has better glide/speed than my current
: boat. I don't need to race but a half of a knot improvement, times ten
: hours of paddling adds up quickly.

Subscribe to the Paddlewise mailing list (www.paddlewise.net has instructions). There are good hull design debates there from time to time between Nick Schade, Matt Broze, and John Winters (and sometimes others).

: My current cloth cover takes on water
: at the gunnel snaps/overlap in small chop/waves so I really want the boat
: to be solid covered with hatches.

Canoe? This is somewhat a separate design question from hull length/shape

: How closely are beam vs waterline length
: related to speed? Will 1 inch make a noticeable difference or does it take
: more.

Longer beam = more wetted surface for the same waterline length.

Round bottoms have the lowest coefficient of friction (least wetted surface).

Fuller ends make the effective waterline length "longer" for a higher wavemaking speed. Finer ends ("pinched") make for a shorter effective waterline, but are more efficient at 'normal' 3kt paddling speeds.

:What factors maintain a fast underwater shape when the boat is
: loaded?

Round hull.

All other things being equal (they never are), hard chines are slower than no chines.

Also consider posting on the Design BBS, as opposed to the Building BBs.

Shawn