: I am looking at the Severn in "New Kayak Shop"

I built a sea kayak like the Skua 16/Yare/Denis Davis tortured ply hull and use it all the time as my sea kayak, day and multiday use.

: A) I can only easily get 4mm okoume, while the plans call for 3mm. Will there
: be any issues getting the 4mm to make the compound curves required?

From memory the Severn is a bit longer (right?) but I'd still want to use 3 mm ply. It does depend what type of ply but my partner has just started another S&G kayak (non-tortured) and she is using 4 mm for the bottom - okoume and I'd not want to try torturing that. However I might try bending a spare piece tomorrow.

: B) Is the only use for the 6mm 1/2 sheet for the bulkheads? Given that these
: are to be used without bending, is there any reason that 5.9mm luaun
: underlay would not be sufficient?

I only use 4 mm (it will be 3 mm for for the new one mentioned above) for bulkheads.

: C) I found a diagram describing how to refine the shape of the bulkheads, but
: no instructions how far forward and aft of the centerline to place them,

If I was doing it I'd put the aft one about 10" aft of the centre and be sitting with a foam pad between me and the bulkhead. The fore bulkhead - not more than 6" ahead of my toes with feet at about 45 degrees. I made cardboard patterns for the bulkheads and trimmed until things fitted, then cut the ply.

: and no description of how they should be shaped (like the approximate
: radii of the deck curves).

I'd have to check the radii I used, tighter for the fore deck than the aft. E-mail me if you need those dimensions. Do laminate the deck beams first so you know the actual finished curve. Also when laying the deck, screw down along the centreline to deck beams and bulkheads. This stops over-bending (humping) and makes sure the deck fits/glues to the beams. Do you want pictures of what happens if you don't?

Alex