God I don't know! What with crash jibes, red-faced men shouting "starboard", echo sounder alarms, ships whistles sounding 5 blasts, engine overheating alarms, women screaming, kids crying - the last thing I would notice would be squeaking floorboards.
Oh yes and very annoying it is.I took pains to level the floors with epoxy putty and in the end had to screw one board down.It's bearable now but I'll have another go this season.
To solve the creaking on some of mine, I put beads of silicone sealant on the bearers. Works really well. (Except that I can't now lift the floorboards!)
I stick rubber strip draught excluder on the frames and then the boards are screwed down at the corners. The individual boards dont squeek but sometimes the edges of adjacent boards squeek.
It doesn't bother me much as I am the person who needs to get up in the night and I always have a cabin where I can shut the door against other people's noises /forums/images/graemlins/grin.gif
I go sailing to get away from all that.
Turn the engine off, sit in the cockpit with a cup of tea and some chocolate HobNobs on a gentle reach………pure R&R.
You buy small, clear rubber beads which you stick to the floors and to the edges of the sole boards. This stops the boards moving and prevents adjacent boards rubbing against each other.
You are in good company. A large Hallberg Rassy owner moaned to me about their squeaking floors when invited aboard..
Planing off some over tight edge contact, rubber strips underneath, anti slam nipples that you find on kitvchen drawers, more framing, thicker boards,ply backing boards between the framing, silicone bead( and masking tape), rubber backed carpets and mats in heavy traffic area,lots to experiment with, hours of fun..