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.
The designs include a pelican, sea-otters, a seal and a sea-lion. Naturally, most of the animals featured are fish, including a blue shark and a stunning vermillion rockfish.
"This exhibit is absolutely gorgeous, [an] accurate representation of the type of animals, fish and vertebrates that I actually see when I'm diving out in the kelp forest," enthused Chad King of Monterey Bay's National Marine Sanctuary.
Kelp Forest is the 11th in a series run by the US Postal Service as part of their Nature of America stamp series. It was drawn by stamp artist John Dawson.
The demonstration was well received by the general public - nicely demonstrating the educational value and beauty of carefully designed stamps.
First-day-of-issue souvenirs were also available for any philatelists who attended.
The exhibition was held as part of stamp collection month.