I have a 68 ft mast. if I had to do it over again a 65 ft would be better.
Many 55ft bridges, some 65 ft bridges, only two 70 ft bridges, and I decided not to risk one of them.
There are few no bridge marinas
, having a tall mast really limits you.
And taking down a 68 ft mast is a no go. Even if I found a crane to do so, that's a long stick on a 40ft boat deck