Stamps and water don't usually mix, and there can be few things worse for a collector than finding that their collection has taken a soaking.
Clearly, nobody told this to a group deep sea divers, who chose to exhibit a series of stamps underwater in the depths of Monterey Bay Aquarium, California.
The swimmers presented a plate featuring a whole series of 44c stamps, as onlookers gazed upon them from the other side of the aquarium glass.
The philatelic series, entitled Kelp Forest, shows 27 varieties of creatures associated with seaweed.