How to Log Your Dives
Why Logging Your Dives Matters
Dive logs are not created for agencies or instructors. They exist for you. Without a record of what happened underwater, you are guessing every time you set up your gear or evaluate a new environment. Logging dives gives you:
- Better buoyancy and trim — You can track what weighting worked with each exposure setup, tank type, and environment.
- Predictable gas planning — Consistent tracking of pressures and dive times allows you to calculate your Respiratory Minute Volume (RMV) and plan gas reserves accurately.
- Equipment tuning — You can identify problems or improvements in your gear configuration over time.
- Environmental comparison — Notes on visibility, temperature, surge, and currents help you plan future dives in similar conditions.
- Proof of experience — Some training programs and operators require verified dives for advanced activities.
- Training and safety insight — Patterns in task loading, stress points, or minor issues emerge only when logged consistently.
What to Record in Every Dive Log
A dive log is not a diary. It’s a dataset. These are the baseline items that should appear in every entry:
- Dive number — Sequential tracking for reference.
- Date, location, and dive type — Environment, site name, and whether it was a drift, wreck, shore, or night dive.
- Start and end pressure — Required for tracking gas consumption and learning your RMV.
- Depth and time — Maximum depth, average depth, and total dive time.
- Gas used — Air or Nitrox mix with exact O2 percentage.
- Buddies or team — Who you dove with and any relevant team notes.
Recommended Details That Improve Your Diving
These entries transform a basic log into a useful tool for improving your diving:
- Weighting — Exact amount, distribution, and exposure suit used.
- Water temperature — Surface and bottom temperatures for suit planning.
- Visibility and conditions — Helps when comparing similar environments later.
- Trim and equipment notes — What worked, what didn’t, and adjustments needed.
- Gas strategy — Reserve pressure, turn points, and any deviations.
- Problems or lessons learned — Any issue worth fixing before the next dive.
Where Divers Usually Go Wrong
Most divers treat logs as a novelty. The problems are predictable:
- Relying entirely on computer auto-logs — These omit weighting, trim notes, environmental factors, and equipment issues.
- Not logging immediately — Details fade quickly, turning logs into partial records.
- Never reviewing old logs — Patterns only emerge when you look back at a series of dives.
- Ignoring weighting history — This leads to repeated instability and wasted gas across trips.
Best Practices for Logging Your Dives
- Log as soon as possible — The first 10 minutes after a dive are the most accurate.
- Use digital logs for consistency — Apps such as Shearwater Cloud or Subsurface simplify data entry.
- Track your RMV regularly — It’s the most reliable indicator of skill progression and gas planning accuracy.
- Note changes in gear — New fins, different wetsuit thickness, or tank type all affect buoyancy and efficiency.
- Back up your log — Export your logbook and store it in cloud storage or a spreadsheet. Do not rely on a single app.
- Review your logs before a new trip — Weighting, RMV, and environmental notes make initial dives smoother and safer.
Using Your Log to Improve Future Dives
The value of a dive log is in how you use it. Before your next trip, review:
- Weighting patterns — Warm water vs cold water vs drysuit.
- Gas usage trends — Your RMV across depth, task load, and environment.
- Trim and equipment notes — Identify recurring problems.
- Environmental matches — Compare similar visibility, temperatures, and currents.
These patterns tell you how to set up your kit, plan gas reserves, and choose the right exposure protection before you even step onto the boat.