How do I log a dive?

Tap the + in the bottom bar, or "Add a dive" at the top of the page on a computer, then choose "Add it by hand". Choose scuba, freedive or snorkel, then add where and when you dived, the details, the species you saw and your buddies.

You only need the place and the date. Everything else is optional, and you can come back and fill it in later.