Had to pull it out and scrape/scrub the bottom on average every three weeks, or the growth would slow the big boat, and for sure the dinghy. Barnacles and weed.
Cruising Ga, SC, NC, the Chesapeake during summer months, about the same.
Only spot over the last 2 1/2 years I DIDN'T have any growth was in the Bahamas.
I've been told Defender sells a bottom paint for inflatables, but haven't seen it.