Grant, Yes, I have used the Oyster white on the advice of others and most recently to upgrade the entire flybridge deck.
The color match to the adjacent gel coat was A-1. However, , the gel coat was polished
to blend with the new paint shine
effect and I didn't attempt any feathering.
However, I do not know how well it would blend to spot painting on a vertical hull side,( within an area of normally weathered gel coating ).
A quart at Lowes is a modest $20 +/- so could be a consideration to attempt a trial match on a smooth surface ( like glass ). and then see what you think.
I have not feathered paint to gel, as spot painting is usually considered an "art"; and know I am not an artist!
In would value your feedback if you explore this ..