How paint on the hull can kill F18 ?

According to builder (we've some in France) only the material; gel coat cost 35€ for a F18, high tech paint,
is more than 10 times more expensive : 400€.

Also the construction process is better adapted to the use of gel coat. (direct in the mould) leading to simpler manufacturing and with lower cost. .

Painting needs to prepare the surface (as a car with mastic) and heavy equipment to finish.
You can use gel coat with painting pistol just diluted to repair as well as paint.

More important to me is that we all know that chemical industry has no limit.
If we accept paint on the hull the certitude is that tomorrow morning appears « magic paint » and also « magic price ».
And then last but not least how make difference between paints? Destructive test?

Yet Mischa's brand new boat is painted.... So you should be very careful what you write.

As for your claims about costs to produce in paint they are equally misguided:-

It is possible to spray newer style paints directly into moulds in the same way as gelcoat, and then the finishing time to produce a hull is actually reduced compared to gelcoat hand finishing which is very labour intensive and slow.

I am not sure what paint you have been quoted, but at 400 Euro material costs it would be 3-4 times more expensive than the very best paints used on Americas cup boats!!

An actual material cost to paint an F18 in top of the line paint is 118 Euro. So perhaps you should review your position...