Looking for correct filler...

Hi all. I am hoping for some advice on a 1984 Laser in excellent shape. If you look at the photo attached, its of the front part of the dagger board shaft where the fiberglass meets the top deck. The BLUE putty fills the area between the shaft and the deck. Most of the seal is in tact all around but a small part has come away and I am concerned it will become a channel for water in the hull. Is there a simple putty recommended to spackle the area that has come away? I'm hoping it's a...

Looking for correct filler...