I have a 1989 Sea Nymph with a 90 horse motor and a Minnecota quest trolling motor. I will be storing it at the dock during the season and I'm not sure about what do use as a cover for the boat. For security purposes I guess covering the trolling motor is more important than than the outboard. I do want it to be fairly easy to put on and takeoff while it's at the dock rather rather than on the trailer. Can I buy a cover online that will cover the trolling motor or do I really need to get these custom-made?