I think you might be reading something into the product description of the kit that isn't there? (I went back and read the description -- which describes the rubber VCP *hatch* option as "airtight.")  The rear bulkhead (plywood, epoxy-coated and filleted into place) is quite watertight. If you build the boat using the flush hatch option, the watertightness of the compartment would be related to how well the gasket seals it... which will result in a generally non-leaking compartment, but not one to which  I would entrust any delicate unbagged electronic gizmos (or an unbagged sandwich, for that matter...)

One could install a forward bulkhead & hatch...make a template of cardboard and then cut plywood to match and epoxy it into place.... (or the same idea with a block of 3 inch mincell foam) but it would be far easier to fill that space with an inflatable float bag --and/or drybags of gear.

Another hint -- if you stuff drybags of gear in the forward part of an unbulkheaded-kakak, it is really, really a good idea to tie a line to the forward-most gear bag to make it easier to get said bag back out of the kayak.... unless you want to be an unending source of amusement for your kayaking buddy as you crawl head first into your cockpit trying to reach the dry bag that got jammed in place way up there beyond where your short arms can reach ... this after your attempts to slide a paddle blade under it to dislodge it only managed to jam it more firmly in place...

I haven't added rubrails, so I have no experience to offer in that area.

Julie K

Julie,

Thank you for your comments.  This boat would be exclusively a day tripper so stowage is not an issue, or advantage.  I have considered the air bags but would prefer a bulkhead.  Does one of the temporary bulkheads fall in an appropriate location or would I need to place one to suit the cockpit and leg length?

Paul

Paul,

No need for a hatch. Cut a plywood bulkhead to fit the space about 4'6" ahead of the rear bulkhead. Install a deck plate in it so you can air out the space and remove any water that gets in. Fix it in place with marine silicone, so you can remove it if you need to later. If you swamp the boat, water pressure will tend to push the bulkhead tighter.

You can see photos of how I did this in my daughter's Ganymede at http://twofootartist.com/ganymede-construction-notes/
Scroll to the June 7 entry near the end of the post and left click on the photo to enlarge it. -Wes

The temporary hull form would need some modification, given that the top of it is flat and the deck is curved, so if you used it "as is" you would have a 2-4 inch gap at the top... (the deck form is a separate piece of plywood....).

If no one else chimes in on this, I can look at the partially built duck in my garage when I get home tonight to see whether the temporary form location is proximate to where you would want it--though I'm thinking, it isn't...it would be far easier just to make one from plywood.....or mincel foam. Wes' idea of using marine silicone to hold it in place is a good one...and another thing to keep in mind if you choose to do a deck plate in the bulkhead instead of a bow hatch is that you would need to install the bulkhead after you attach the deck to the hull, since you need to reach in there way up to the bow to fillet and tape the hull-deck seam....(think, long stick ....and even more amusement for your kayaking buddy....)  unless you decide to install a shear clamp to facilitate adding your desired rub rails. 

Julie K

Hi Paul,

I put a forward bulkhead with a six inch dia. deck plate in my WD12 hybrid. I put it 30 inches back from the tip of the bow.  I used silicone to seal it.  It works great. 

I did this so that I can fish in late fall and early spring in cold water. I just do not want to be caught off guard in cold water. If I can not paddle to shore with a wet cockpit, then the boat is useless to me.

Lou

The closest temporary hull form on the WD 12 is located 47 inches forward of the aft bulkhead.....The other good news is that would be really easy to do a butt joint to join the temporary hull form to the corresponding deck form (they match up perfectly...), and trim it down all around to fit where you really want it ...thus it would be quite possible to form a forward bulkhead using only the wood supplied in the kit.

Julie K