Rub Rail Sealer

I need to reseal the underside of my rub rail on my Ranger 372V fiberglass boat. What kind of sealer do I need to get, silicone or something else?

I noticed that there isn't any on the top of the rail, is this normal or has it all been removed?

Thanks in advance for all the help.

Tony

100% marine silicone... run a bead with your gun.... then get a spray bottle of water and spray the silicone and run your finger along it and press it in so you get a good seal... The water helps keep the silicone from sticking to your finger.