We recently became aware of this same problem, and eventuallly learned we could get riders from State Farm for our four canoes. We needed a separate one for each canoe, at a cost of $25 - $35 each, per year. Otherwise our coverage was extremely limited, even if the canoes stolen from a locked garage. If they'd been stolen from a cartop, we'd have been out of luck.

Now all four canoes are covered against theft, but also against things like "collision, sinkage, and capsizing." The policies are designed for motorboats, but they can be used for a non-motorized craft.

My suggestion... If your agent stubbornly insists otherwise, keep your kayak but shop for a different insurance agent. Good luck!

Al