Someone asked the question about mounting and dismounting their Humminbird units from the gimbal mounts, stating it was a hassle to mount and dismount them.
I basically had the same issue and I always transport my units inside of the truck. After playing with it for a while, found that by totally removing the knobs, it makes easy to mount and dismount the units, for a while I always screwed the knobs back into the unit, now I put them in a door pocket and life is good.
The first think I do after getting to the lake is to place both units in the gimbals, install the plugs and then put the knobs in place and set the angle of the units. This is really quick and easy to mount and dismount.
I do not think that I would take the chance of installing the units on the boat when if it was already on the water, too much money to take that chance.
George