I would certainly believe it easily can be 70%. Been to other seaside towns before when visiting family and especially in the main part of the town everything is now rented out.

I suppose I do also live in a seaside town but it isn't popular with tourists, we have a beach but as its on a peninsula and just like the rest of the beach that stretches on for like 100km or so around the coast there is very little reason for anyone to come here for it unless they live here.