I am hoping Matt Miller and the Hobie techs will be able to advise on this question.
Essentially, it involves the question of putting a small amount of non-toxic anti-freeze (say 1/8 to 1/4 gallon) into each H16 hull for the winter. This is what we sometimes do in the bilge of the big boats/yachts around here. The anti-freeze (the pink RV Plumbing stuff) guarantees that any trapped or missed water will not freeze hard enough to cause any damage.
I am interested in doing this with my H16 because I have to store my Hobie relatively level (as opposed to elevated for drainage) and it seems there is always a little H20 present in the hulls from condensation. Whether this is enough errant water to cause freezing damage I do not know, but I`d rather not worry about it through the winter.
I have viewed the cross-section photo of the inside of the H16 hull and it seems to me that this may be a good solution - one which will allow me to safely store my Hobie as I have described - regardless of errant H20.
Also, the photo seems to illustrate that the foam core does not extend as low as the keel; thus minimizing any seepage issues into the core that could occur from an unseen inner hull defect.
Any thoughts on this? I would also leave the drain-plugs in - but very loose.
Dave