Ok, top postin?

Some thoughts that may or may not help...
(My glass experience is all aviation related)

First, this is a job for epoxy - only.

Getting a good secondary bond with polyester or vinylester is questionable.
Epoxy WILL stick well. Even West is better choice that poly, although I
UNrecommend West for glass lamination work.

I'd use an air powered die grinder to carve into the existing glass enough
that any contamination or fatigued areas have been removed.

Do this neatly so as to leave a slightly recessed trough in the critical
areas, and enough bare glass surface around the "wound" for good overlap
of the added material.

Thicken some epoxy resin with cabosil or flaked cotton to the consistency
of peanut butter (these are good structural fillers where micro balloons
are not). Trowel this goo into the area to be covered and use a tongue
depressor (or ?) to make a radiused corner - rather than a square one.

I'd use woven glass tape instead of mat, but on a boat where weight is not
as critical - well - your call. But if mat is used, do consider a woven
"close out" layer over the mat.

Lay first layer of glass (pre-wetted works well) over the filler, overlapping
a couple of inches onto good surface. Smooth out flush and make sure to get
all air bubbles out. Tapes can be "pulled" quite a bit to lay into the
compound curve without snipping gores. Try it dry first to get the feel.

Lay on more layers of glass, with each layer overlapping an inch or two
farther onto bare clean glass. This acts to close out the edges of the layers
underneath, thus protecting the repair from water infusion along the exposed
fibers.

Lastly.

Go to the outside and repeat the above.
Carve off the gell coat down to clean glass - deep enough to allow two or
three layers of cloth or tape.

This puts the repair in double shear, and stops the crack from flexing.

Bare resin outside will open up right quickly, and the whole thing is a waste
of time an money and effort.

The LAST layer on the outside is a sacrificial layer that can be sanded
off smooth. It should be slightly above the surrounding surface and sanded
down flush as possible.

A bit of Bondo, or micro will fill the tapes and any dips and give a smooth
surface for painting.

There is NO reason at all for a fiberglass repair to be visible - much less
ugly.

Well, that's my 2 cents worth of free advice.

I know is sounds like a lot of extra work, and I guess it really is to a
point. But it will be something you'll have to POINT out - and then they
might not believe you.

Happy scratching!

Richard