Probably the best Marine Adhesive Sealant I have ever used. Takes forever to cure but once it does, very strong watertight bond. I have used this to seal screws into a transom, seal other stuff where a watertight seal is needed and never a problem. I have also used this to glue bimini top brackets (along with screws of course) to a boat. Anything I attach to a boat, inside or out, I use this 3M 5200 adhesive as a precaution against vibration loosening the attaching screws. Just keep in mind that it might take a week for this 3M 5200 to fully cure. If you need a faster cure, use the fast cure version as that is almost as strong. I would also look around at prices as you might get this cheaper.