We bought two of these to use for snorkel gear and beach toys on a recent cruise - they worked great.  Our 9yo son carried one, I carried the other, and am glad to report no problems at all.  They were durable and we were able to fit a LOT of stuff inside them - we use the "shorty" type of fins and were able to fit a pair of those along with two snorkels and two masks in one backpack, along with other assorted stuff.  Highly recommended!