Help

Before you download

The Mac package will not open: “the application cannot be opened”.

Almost always an Intel Mac. MyDiveLog is built for Apple Silicon only: the package installs anyway, and then the app will not start. You need an Apple-silicon Mac and macOS 12 or later. There is no Intel build, and none is planned.

Windows says it doesn’t know us.

“More info” → “Run anyway”. The file is signed, just not for long enough for Windows to have formed an opinion about us — it happens to anyone who does not pay for EV certification. The SHA-256 fingerprint published next to the package tells you whether the file you have is ours.

Android asks permission to install from this source.

It is the same question it asks for any app from outside the Play Store. The APK cannot vouch for its own origin: the SHA-256 fingerprint in the release notes can.

The Linux package will not install: libwebkit2gtk-4.1-0 is missing.

The .deb needs WebKitGTK 4.1, available from Ubuntu 24.04 and Debian 13 onwards. Older distributions only have 4.0 and this package will not go in — that is not a fault of the package, that library simply is not there. On Ubuntu 22.04 there is no route for now.

I am on Arch or Manjaro: the .deb will not install.

There is no dpkg, but the package can be repackaged for pacman with four commands — nothing to compile, the binary is the same:
sudo pacman -S --needed base-devel
mkdir mydivelog && cd mydivelog
curl -LO https://raw.githubusercontent.com/matteoferrando/MyDiveLog/main/linux/PKGBUILD
makepkg -si
makepkg stops if the file’s checksum is not the declared one. Tested on Manjaro.

Can I install it with Homebrew?

Yes, from our own tap:
brew tap matteoferrando/mydivelog
brew install --cask mydivelog

Your dive computer

I press “Find my computer” and nothing shows up.

Nine times out of ten it is the Bluetooth permission. It is the first thing that stopped this application’s first outside user, and the error was not clear: the app now says where to grant it. On macOS: System Settings → Privacy & Security → Bluetooth. On iPhone: Settings → MyDiveLog → Bluetooth. Then check the computer is on and in pairing mode: many only make themselves visible for a few minutes after you ask them to.

My computer is not in the list.

From a phone only Bluetooth LE is reachable: serial ports and USB do not exist there, and classic Bluetooth is reserved for system profiles. Of the 356 models libdivecomputer describes, about a hundred speak BLE, and that is the list. If your computer writes a file — UDDF, Shearwater, Subsurface, LogTRAK, Garmin FIT, CSV — you can import it instead, and that road is just as good.

I downloaded twice: will dives be duplicated?

No. From the second connection on it takes only the new dives, and the ones already there are enriched rather than duplicated. The same holds when one dive arrives by two different roads — over Bluetooth and from an exported file.

Two computers show different times. Will dives be split in two?

No: the offset between the two clocks is inferred across your whole logbook, and the match is confirmed on the shape of the profile, not on the timestamp. Every dive lists the sources it was built from, so when a value is missing you know which computer never wrote it.

Your data

Where are my dives?

On your device, in a SQLite file you can open with anything. On a Mac it lives in ~/Library/Application Support/it.ferrando.mydivelog. We keep no copy: if you do not sign in and do not press Sync, nothing leaves the device.

How do I back it up?

Settings → full JSON backup. It is the only one that puts everything back the way it was, gear and certifications included. The UDDF, CSV and KML exports are for taking dives elsewhere, not for rebuilding the archive.

Do I need an account?

No. The logbook opens, imports and analyses without ever seeing an account. Signing in — with Apple or Google — does one thing only: keeps the archive aligned across devices. And even then, syncing starts when you press it.

I want to leave: can I take everything with me?

JSON backup, UDDF, CSV and KML export, logbook printing. And the archive is a SQLite file: worst case you open it with anything and take the tables by hand.

The numbers

The calculations do not match my dive computer.

That is normal, and it is right to look at them with suspicion. Every dive computer uses its own implementation, and conservatism settings rarely line up. MyDiveLog uses Bühlmann ZH-L16C with gradient factors, and under every number it states how reliable it is and how many dives it rests on.

The VPM-B plan is shorter than V-Planner’s.

Yes, by 5 to 10 per cent, and it is stated inside the application too. This is not a calibration: it is a difference we have not explained yet, and until we do it stays declared rather than hidden.

Can I use it to make decisions in the water?

No. MyDiveLog is not a dive computer. The calculations exist to study the dives you have done and prepare the ones you are going to do: they do not replace your dive computer, your training or your judgement. Scuba diving carries risks, including death.

The logbook and the law

How do I get the PDF logbook page?

Open the dive and press Print this dive: out comes a page with the thirteen entries the law asks for, the profile drawn, and the guide’s signature. It works from the phone too, and you send the file to whoever asks without going home first.

Is the app “legally compliant”?

It holds the fields the rule lists. Compliance, though, belongs to whoever fills the logbook in, not to a program — and the law leaves more than one question open. The page on the logbook law writes them all down, including the ones without an answer.

Updates and reports

How does it update?

Mac and Windows tell you when a new version is out; downloading and installing it is your call, and every update is signed. Android and Linux do not: you get the file again from here. If you installed from the App Store or the Mac App Store, Apple delivers it like any other app.

I found something wrong.

Tell us here: two lines are enough. This application’s first outside user found a real defect by pressing a button, and that defect was out of reach of every automated test. Reports are how this project gets better.