Fiberglass Repair/Restoration Question

I recently picked up a fiberglass kayak circa 1980, and have two question about what I'm seeing.

First, on the hull, there are areas where some coating has peeled off. More exactly, there are some areas where that coating remains, while most of the hull is free from any trace of the coating. I don't know exactly what it is/was or why it was there, much less if it needs/must be reapplied. (See Pic 1 and 2. The problem is obvious here. At the center of the Pic 1 is an area I removed coating from today; about the size of quarter.)

One of the stranger things (to me) is that the coating can be found almost nowhere on the sides of the hull, but runs the length down the center. (See Pic 3. The dark areas are coated.)

I cannot say much more, but will happily answer clairifying questions.

Second, and related to the first, is that the deck appears to have heavy gel coat, while the hull is nearly free of any obvious coating, save the flaking stuff mentioned above. (See Pic 4 ) Because the water line is about 2-3 inches below the seam shown in the picture, I'm a bit confused about why the deck would be so thickly coated, and the hull (seemingly) not at all.

Last photo is just to show what she looks like in full. I have no reason to believe she's not sea worthy today, although there are a few weak spots on the hull, and a small crack on the deck, both of which I'll patch ASAP. Over the winter I plan to do some work to make her pretty again, add some lashings, and a few other upgrades, along with whatever I learn from ya'll about the coating question.

Thanks for your time and wisdom.

 

Its complicated. The best advice is that anything that looks a bit suss, needs to be sanded off to a sound, roughened surface. I would then forget about trying to figure out what the stuff is, and just use Epoxy for any repairs, because it will stick to anything, and you cant be that confident with Polyester.