How to Log a Scuba Dive: A Simple Routine

Logging a dive takes two minutes if you do it right after surfacing. Wait until the evening and half the details are gone. Here is a routine that works, whether you write on paper or in an app.

Log while your computer still remembers

Your dive computer holds the objective numbers: max depth, dive time, water temperature, and your surface interval. Copy them before you do anything else. Most computers keep a log history, but scrolling back through ten dives on a tiny screen during a surface interval is nobody’s idea of fun.

The subjective details fade even faster than the numbers. The name of the swim-through, the eagle ray that passed at the safety stop, the reason your left ear was slow to equalize — write those down within the hour or accept that they are gone.

The core entry

Every dive log entry needs these basics:

Date and dive number. Your running total is proof of experience for future certifications.
Site name and location. Be specific: “Shark Point, Koh Phi Phi” beats “Thailand.”
Times and depth. Time in, time out, total dive time, max depth.
Air. Starting and ending pressure, plus tank size. This is how you learn your consumption rate.
Buddy and guide. Names matter when you want a signature — and when you want to dive together again.

If you want the complete checklist, including what you can safely skip, I wrote a full guide on what to record in a dive log.

Add what made the dive yours

The basics prove the dive happened. The rest is why you will reread the entry in five years:

Conditions. Visibility, current, surge, water temperature. Patterns emerge over time — you will learn which sites work in which season.
Wildlife. What you saw, roughly how big, and where on the dive. If you could not name a species, note its shape and colors and look it up later. My guide on identifying fish while diving covers a simple method.
One sentence of story. Not an essay. One line — “octopus changed color three times trying to shake us off” — is enough to bring the whole dive back.

Get it signed

If you are working toward a certification, have your instructor or guide sign the entry. Agencies accept both paper signatures and digital logs; when in doubt, ask the dive center what format they want to see. Many divers keep a slim paper log purely for stamps and signatures and do everything else digitally — I compare the two approaches in paper vs digital dive log.

Make it a habit, not a chore

The divers who stop logging usually stop because the format demands too much. Keep the bar low: numbers plus one sentence. A streak of short entries beats three beautiful pages followed by silence. Boat rides and surface intervals are ideal logging windows — the dive is fresh and you are not going anywhere.

How I handle it in Tortuba

I built Tortuba because I kept meeting the same wall: the logbook that felt like homework. Tortuba keeps the entry playful and quick — duration, depth, air, site, buddies, and conditions in a few taps, all offline, so it works on a boat with no signal.

The part I care most about is the wildlife. Tortuba’s built-in guide covers 10,000 species, searchable by body shape or by name, so the “grey fish with the yellow tail” gets a proper identity before you forget it. Each sighting attaches to the dive, and you can browse my animals index to see where species are reliably spotted. When words fail you, a writing coach nudges the story out — a toothy Shakespeare, no less.

Your buddies go in too, even if all you caught was a nickname, and teammates or instructors can sign your logbook in the app. A refresh is on the way — new UI, cloud sync — but the habit works today: surface, tap, done.