REEF Mats are designed to support thousands of pounds without sinking. Your whole family, extended family, friends, neighbors, friends of friends, event pets will be able to float all day!
The short answer is. There really isn't a safety limit to the weight of each mat, but at the following weights and capacities, the mat will start to submerge a bit:
REEF 48: ~800lbs (3-4 people)
REEF 85: ~1200lbs (4-6 people)
REEF-123: ~1600lbs (6-8 people)
REEF-129 ~2400lbs (10-12 people)
REEF HEX 82: ~2000lbs (8-10 people)
REEF HEX 101: ~1600lbs (6-8 people)
REEF HEX 112: ~2000lbs (8-10 people)