so do you know the sizes?
Nope, measure your boat. All you really need is the distance between the front and rear crossbars and the distance from the front crossbar to the bow. The trailer crossbars should be approximately in line with the boat's crossbars. The trailer axle should be located approximately centered between the crossbars. The trailer tongue should be about two to three feet longer than the distance from the front crossbar to the bow. Also, a H16 is 6" wider than a H14, so you need to make sure the crossbars can accomodate the wider boat. It isn't rocket science- bigger is better (to a point). Too small will be the bigger problem. If you're buying a Hobie 14 trailer, there's a chance it would be too small. A Prindle 16 trailer would probably be fine. Also verify the trailer and axle load ratings.