The underwater photos are not officially part of a collection but your Sims can still collect and display them in their home all the same. Underwater photos can be taken while scuba diving after purchasing an Underwater Camera for §1,000. Mermaids and Sims with Fitness skill level 3 or higher can take underwater photos while free diving if they have the Underwater Camera as well. There are a total of 10 underwater photos. Sims can name their underwater photos, make copies of them, and sell them. Sims with high Photography skill will take better quality underwater photos.