yes, the Panasonic panels do not have a marine guarantee. If they were installed on a house they are guaranteed for 25 years. My take on that is, if they fail after 10 years I already have got my moneys worth. They were the cheapest part of setting it all up. The MPPT is almost as expensive. And the drilling of the holes in the arch, preparing the arch for the panels, and pulling the wires, never mind the 100 hours of research beforehand, that took far more time.
If they fail and need replacing, it would be a much simpler job. Wires, MPPT, etc all in place.