Best coaming to deck sealant

My Romany has a few leaks between the coaming and deck that are mainly a problem when rolling but also sometimes when paddling in rough water. What sealants do you recommend? Thanks. Len

This is a FG boat and coaming?

Best coaming to deck sealant
Yes - the deck, coaming and hull are fiberglass.

3M 5200
or other equivalent urethane.

You could use thickened West G-flex.
It has high adhesion and is somewhat flexible.

If you are “caulking”…
…the underside of the coaming where it meets the deck, Use the smallest bead opening that will bridge your gap…do ten inch sections at a time and feather backward from where you started with your finger (either with several vinyl gloves or paper towels and lacquer thinner to clean the excess off your finger each time…the beauty of 4200 is that can be removed if you ever need to…5200 is there forever.

Definitely use epoxy
A leak around a coaming could indicate a structural problem, especially with NDK boats, which are notorious for such problems. Clean and rinse the area well, make sure it’s completely dry, then flow epoxy into the joint.

Thanks everyone for the advice.
I just did the seam with 3M 4200 and will test it tomorrow. Len