It is believable and true in our area this time of year, even with fresh anti-fouling. As I used to dive for a living and still have a diver on staff, I hear on a weekly basis " I just painted it last year" (month, week) "why is it not turning up"
and also..." your refrigeration technician fixing the air conditioning in the V berth must have done something to my diesel engines in the cockpit because the boat is not turning up and I just painted it last year"*
also, a cheaper bottom paint job down the street is not always a good bottom paint job, especially when someone uses a roller to put paint that is intended for a properly prepared fiberglass bottom on metal *running gear that has only been pressure washed (aka "cleaned and prepped") and the paint peels off the running gear during the first trip back to the slip...
just my rant and two cents for the night !