Moisture in cockpit and foredeck

I know nothing of your boat, but I suppose we are talking of cored construction - either with balsa wood or some PVC material inside, right?
If so, the former suggestion is certainly more radical and conclusive, but I can easily imagine that it's a helluva job.
The latter is certainly easier and less invasive, but depending on the core conditions, it could be very little effective, because the epoxy resin is likely to "trap" forever some wet areas inside the core.

If you have a decent access to the underside of these decks/floors, you could try the latter, but with a twist:
First, drill the multiple holes only on the bottom GRP layer of the sandwich.
Second, rather than inject epoxy right away, leave the holes open, and monitor the situation over time. You could see a bit of liquid dripping out from them, and if so, just leave the holes open and let them drip - the longer the better. Mind, it could take months if not years, but eventually you should see a decrease in moisture readings (particularly if your boat is in a warm and sunny climate). And only at that point, you could inject some epoxy resin in the holes and seal them all - though you might as well just forget them and leave them open.

There's a third alternative worth considering, which is doing nothing at all.
I mean, are all parts of the deck hardware firmly attached and sealed now? And is the cockpit deck solid, with no flexing areas?
If yes, I'd be tempted to follow the good old "if it ain't broke, don't fix it" rule...

Just to avoid possible misunderstanding, don't expect a lot of dripping from those holes.
Cored decks can't hold gallons of water, because there are no void spaces inside - well, there shouldn't be any, at least!
But some tiny amount of rain or washing water can find its way into the core, for whatever reason.
And if/when it does, it's likely to remain trapped, hence soaking the core material, over time.
So, by drilling several holes on the bottom GRP layer, you are unlikely to see a lot of liquid pouring out.
Maybe some drops, if that.
But the idea of having holes on the bottom and leave them open for some time is mostly meant to dry out the inner core.
In fact (and I forgot to mention this before), if the problem is in specific areas rather than widely spread, you could also leave some heater blowing warm air under the holed area, to speed up the drying process.
Good luck!

Several companies up and down the east coast offer core drying for yachts. Dry Boat, Dry My Hull & Dry Hull seem to be the major players and I believe Ship Shape TV has a few U-Tube videos on a couple of these companies doing their thing. I believe that at least one of these companies sell their proprietary core vacuum systems on-line. I did run into a Rube Goldburg core drying system a few years ago being used on a cabin trunk for window leaks that consisted of two AC vacuum pumps attached to an accumulator with vacuum switches in line that had the suction lines attached to generic rubber vacuum cups with a hole drilled in the top to accommodate the vacuum lines. They drilled a few 1/4' holes low along the cabin trunk to deck joint and had them attached and running cycling on and off on the vacuum switches for a week or so and had to empty the accumulator of some nasty looking fluids a couple of times. If you drill down online, I'm sure that you'll find some type of home brew core vacuum system using store bought parts to cobble together.

Drying out the core is fine, IF the core is in good condition. The cockpit core is mush. It needs to be opened up and replaced.

After removing teak cockpit deck found the main hatch was wet so it was opened up, dried out, and rebuilt. Pre purchase survey showed two wet areas on the front deck which they cut open and cleaned out today. Apparently they need to remove a section of headliner as the 4 bolts holding the port cleat are loose but just spin so suspect there's an aluminum backing plate with locking nuts. No idea how it got wet in there.

I have local company doing the work at my dock working stern to bow started with removal of the old teak on deck & gunnels, refinishing the fiberglass that was under it with new Awlgrip with combo of fine and course non skid added. No idea what filler they used in the hatch as that had been taken back to their shop but will see what they use on the front deck. I believe they will use the original glass all cleaned up in my yard.




Getting all the brown glue up was best with use of a heat gun but in some areas it also took up gelcoat creating more work.

Ten years of teak maintenance on the last boat convinced me no more exterior wood.

While removing the exterior teak, interior carpet replaced with teak & holly.
Weighted buckets of water while cement dried.

I've seen 80 ft. plus, yachts being painted out on the main intracoastal waterway but never paid attention to the method. Several years ago I had my then 38' Bertram painted from rub rail up, while at my dock; all via spray but took the guy forever as the weather played into the job. More recently I had all of the dark green stripes on the 46 including the one at the top of the Tuna Tower repainted in gray with gold pin stripes while at my dock. The painter has a small Airless sprayer that eliminates nearly all overspray, and I think the rest dries in the air while still within short distance from the boat. My smaller boat's on a lift just a few feet away and no overspray. On the list still is hull paint from rub rail down Fighting Lady Yellow back to original white but painter said he wants to put her in a yard and tent after finished with the current at the dock projects.