Paper logbook or dive log app? How to choose, or use both

What paper does well

A paper logbook is simple. It needs no battery and no signal, it never asks you to update anything, and it still opens in twenty years. It is also where instructors and dive centres have traditionally signed and stamped a dive, and many still expect to see one for a course or a first dive at a new centre.

Writing a dive down by hand also makes you slow down for a minute and think about it, and some divers like that.

Where paper falls short

Paper cannot add things up. Your total dive count, your hours underwater, your deepest dive and your air consumption are all sums you do yourself. It cannot search for the dives at one site, or show you which month the water was warmest. And it exists in one copy: a logbook lost on a boat or damaged by water is gone, together with every dive in it.

What an app adds

• Sums and trends. Totals, dives per year, depth and time charts, and with the right figures logged, your air consumption.
• Search and filters. Every dive at one site, every night dive, every dive with a given buddy.
• Import from your computer. Depth, time and the profile can come from a file instead of memory.
• A copy somewhere else. A synced or exported log survives a lost phone, a lost bag or a flooded locker.

An app also has downsides. It depends on a device, and your log lives in that product unless you can take it out. That is why export matters: ask any app how you get the dives out before you put a hundred of them in.

Use both: print the app

You can keep the numbers in an app and still have paper to sign. Loggerfish has a printable logbook: choose the whole log or a range of dive numbers, set how many dives go on each page, and print it or save it as a PDF by choosing "Save as PDF" as the printer. Every dive has a column for a buddy or instructor to sign, and the pages carry running totals the way a paper logbook does. Printing is free.

For a course, Pro adds a logbook PDF for instructors that summarises your experience and marks which dives were recorded by a dive computer, which a buddy confirmed in Loggerfish, and which you entered by hand, with a box to sign. Loggerfish only prints what you logged; the signatures and stamps are still your instructor's.

Use both: copy paper into an app

If you have a shelf of old paper logbooks, you can bring them in without a file. Loggerfish has a batch entry grid for past dives: one row per dive, with date, time, site, country, maximum depth, bottom time, water temperature, visibility, buddy and notes. You can type into the grid or paste rows from a spreadsheet, and any problem is reported by row and column instead of being guessed at. You see a preview before anything is saved, and you can undo an import.

Do it in batches, a logbook or a year at a time. Keep the paper: it is still the original.

A sensible setup

1. Log in the app, straight after the dive.
2. Print the pages when a course or a dive centre wants a signature.
3. Keep the paper logbooks you already have, and copy them in once.
4. Export your log now and again, and keep the file somewhere that is not your phone.

Logging, import, printing and every export are free. Analysis such as air consumption over time is part of Pro, the optional paid plan.