Starting in fiberglass and gelcoat repair

Hello,
I'm new to the DS world and working on my 1965 ds 1 as I'm also getting some sailing in this summer. I dont have experience with fiberglass, gelcoat or epoxy but I'm learning from reading here on this list, elsewhere on the internet and mostly the west systems how to guides.
I discovered this opening off to the port side, where the hull and centerboard trunk meet. I can't tell if the gap that's apparent there is between layers of fiberglass or just between the right angle formed edge of the hull and a never attached, underlying fiberglass layer. It may be hard to tell, this open space is about 1 to 1.5 inches long.
I was planning 3 days on the Columbia river this weekend and wonder how I should take care of this. Can i just fill this up with epoxy? I'm afraid if I start sanding the right angle aspect the hull forms, then I'll just expose a small channel running the length of the centerboard trunk? But if that's the thing to do ill sand it away and take the next steps.
P.s. I'm aware the cb itself needs some work. Thank you all for your help!
I'm new to the DS world and working on my 1965 ds 1 as I'm also getting some sailing in this summer. I dont have experience with fiberglass, gelcoat or epoxy but I'm learning from reading here on this list, elsewhere on the internet and mostly the west systems how to guides.
I discovered this opening off to the port side, where the hull and centerboard trunk meet. I can't tell if the gap that's apparent there is between layers of fiberglass or just between the right angle formed edge of the hull and a never attached, underlying fiberglass layer. It may be hard to tell, this open space is about 1 to 1.5 inches long.
I was planning 3 days on the Columbia river this weekend and wonder how I should take care of this. Can i just fill this up with epoxy? I'm afraid if I start sanding the right angle aspect the hull forms, then I'll just expose a small channel running the length of the centerboard trunk? But if that's the thing to do ill sand it away and take the next steps.
P.s. I'm aware the cb itself needs some work. Thank you all for your help!