Was inquiring with a marine dealer on methods to mount a fish finder to a fiberglass boat (e.g. no holes) and he said a lot of people were using Ram Mounts. Well never having heard of them I did a bit of poking on the internet, and they are ingenious little things. Suction cup mounts, rail mounts, hard mounts, arms, fishing rod holders, cup holders, camera holders, ipads, anything you can think of really.
Alan