Most cruising boats are fibreglass, so most cruising repairs are fibreglass repairs. The good news is that GRP is forgiving and repairable almost anywhere, and France has no shortage of people who can do it well. The catch is that "gelcoat repair" covers everything from a five-minute cosmetic fill to a six-week osmosis job that strips the boat back to bare laminate, and the visitor who does not understand the difference can be talked into far more, or far less, than the damage warrants.
Here is how I think about it, having put more than one French yard's gelcoat man to work over the years.
Four jobs that all get called "gelcoat repair"
Cosmetic scratches and scuffs. The dock rash from a clumsy berthing, a fender that slipped, a careless neighbour. These live in the gelcoat only and do not reach the glass. They are filled, faired and colour-matched, and on a small area this is an hour or two of skilled work.
Crazing and star cracks. The fine spider-web cracking around fittings, hatch corners and high-load areas. Cosmetically annoying, sometimes a sign of flexing underneath. The repair is to grind out the cracks, fill and refinish, but a good yard will also ask why the area is flexing in the first place.
Impact damage to the laminate. When the glass itself is cracked or holed, from a grounding, a collision or a hard knock on a pontoon. This is structural. The damaged laminate is ground back to sound material in a tapered scarf, rebuilt with new glass and resin, then the gelcoat is restored on top. Done properly it is as strong as the original.
Osmosis. The blistering below the waterline when water has worked through the gelcoat into the laminate. This is the big one, and the most over-diagnosed.
The osmosis question, honestly
Osmosis gets visitors into trouble because it sounds terminal and the full treatment is expensive. The full cure is real work: the underwater gelcoat is ground off completely, the exposed laminate is dried over weeks until a moisture meter reads low, and the surface is rebuilt with an epoxy barrier rather than the original polyester. The boat is out of the water for at least six weeks, often a whole season, and done properly the repair should last around twenty years. Professional treatment is commonly priced per foot of length overall, with figures starting in the region of 15 to 20 pounds per foot quoted in the trade and rising steeply with the size and severity, so on a 35-footer you are into a four-figure job before you start.
That is why diagnosis matters more than anything. A handful of small blisters that appear after launch and shrink again is not the same as widespread wet laminate. A good French yard will use a moisture meter, tap-test the hull, and tell you whether you are looking at a few cosmetic blisters to grind and fill or a genuine osmosis problem that warrants the full treatment. If a yard quotes a full strip-and-dry on the strength of three blisters, get a second opinion. This whole topic deserves its own treatment, which is why I wrote it up separately in the guide to osmosis treatment in France.
The vocabulary
Gelcoat is le gelcoat (the English word is used), fibreglass or GRP is le polyester or la fibre de verre, a scratch is une rayure, crazing is le micro-faiencage or les fissures, a blister is une cloque or une bulle, and osmosis is l'osmose. A fibreglass repairer is a stratifieur (from stratification, the laying-up of glass), and a workshop doing this work advertises stratification or reparation polyester. Colour matching is la mise en teinte. Walk into a yard and say "j'ai des rayures dans le gelcoat a faire et quelques cloques sous la ligne de flottaison" and you have described scratches in the gelcoat and a few blisters below the waterline.
What it costs and how it is billed
Skilled GRP work runs at the usual French coastal yard rates of roughly 50 to 54 euros per hour including VAT, and the standard French VAT rate of 20 percent is in the figure you are quoted as a private owner. Gelcoat work is labour-heavy because the time goes into preparation and finishing, not the materials. The colour match alone on a faded old hull can take real effort.
Most jobs other than osmosis are billed by the hour plus materials. Ask whether the quote is TTC (VAT included) or HT (before VAT), and on any structural laminate repair ask to see how far the yard intends to grind back, because a properly tapered scarf is the difference between a repair that lasts and one that lifts at the edges. For larger refit-scale work the VAT treatment can vary, especially for non-EU visitors on temporary admission, which I cover in the article on VAT on boat repairs and refit in France.
Finding the right yard
Gelcoat and laminate work is bread and butter for almost any French haul-out yard, so this is one repair where you are spoilt for choice. The capitainerie list and the chandlery counter will point you at the local stratifieur, and the haul-out yard usually has its own in-house GRP team or a regular subcontractor. If you are lifting out for the job anyway, choosing the right yard matters more than chasing the cheapest hourly rate, a point I made in the guide to hauling out as a foreign owner at a French yard.
One word of warning on colour. Older boats fade, and a fresh gelcoat patch on a 25-year-old hull will often show no matter how good the colour match, because the surrounding gelcoat has aged. A good yard tells you this honestly before they start. On a tired hull it is sometimes better to accept a clean structural repair and a slightly visible patch than to chase a perfect match that will never quite happen.
What you can do yourself
Small cosmetic gelcoat work is well within a competent owner's reach. A gelcoat repair kit with matched pigment, the right hardener, masking tape, wet-and-dry paper in a range of grits and a tin of cutting compound will let you fill and fair minor dock rash at anchor. Carry one. It saves yard visits for the trivial stuff and keeps small chips from turning into water ingress over a season. The kit overlaps with the wider maintenance and tool list in spares and tools to carry when cruising France.
What I leave to the yard: anything that has reached the glass, any structural laminate repair, and the entire osmosis question. Get those wrong and a cosmetic problem becomes a structural one. Get them right, and a fibreglass boat is the most repairable hull there is. That deep, accessible web of GRP trades is one more reason France is an easy country to keep a boat in, which is the running theme of my overview of chandlers and boat repairs in France for the visitor.
