The PT 11 and Spear are very dependent on gaskets. The 11 has a hull gasket, a hatch gasket, and a trunk cap gasket. The Spear has two hatch gaskets and a trunk cap gasket. 
We are fairly proud of the gasket systems we have developed, but nothing is ever perfect. The latex tubing gaskets set in notches of the correct depth work amazingly well, but we have had some trouble with two things:
One of the issues is that gluing the latex gaskets is difficult, so they can come loose.
We have tried just about every adhesive and have finally found one that works much better than the contact cement method described in the manual. More about that in a soon-to-come blog post.
The other thing we have recently had happen is the outer face of the gaskets becoming stuck to their mating surfaces. This seems to be a problem mostly with the trunk cap, where the gasket is pressed much more firmly, due to the gasket notch depth being limited. We tried coating the outer face of the gasket with a few different lubricants, Vaseline being the one that seemed to work.
We will do a blog post about gluing in new gaskets with the adhesive we have found to work, but first we would like feedback on gasket issues from our customers. -What issues have you had?
-Do you need a new set of gaskets for you boat?
-If your gaskets are working fine, consider rubbing a light coat of Vaseline (or maybe you know of something that will work better) on the outer face of the gaskets, especially if your boat is being left assembled for long periods of time.
Thank you!
RB