L&VW
Well-Known Member
Good point--especially as I'm presently in the process of replacing two forward blocks of a Sunfish that was gifted to me by a neighbor following Hurricane Irma. This Sunfish had a hard life by two growing boys and three hurricanes. (The splash guard had been formerly replaced and replaced again
by me as a gesture--as I had been welcomed to borrow it on occasion).The factory-installed wood blocks are held somewhat loosely by weak straps of fiberglass tape of the "mat" variety. (non-directional fibers).
Before moving or turning the boat again, I'd replace one screw of each hardware piece to keep each wood block within reach. (A loose wood block can be heard dropping around inside the hull as it is turned).
Except in my case, there's no evidence of wood blocks, but a lot of sawdust inside.
Since this is Florida, I suspect the cause was insect "grazing". 
Because the blocks are all deck-based, I'd secure the blocks (if possible) then dry the boat upside-down.
For a primer on replacing wood blocks, scroll upwards to comments #13 through #20.