DC Log privacy policy

Your logbook stays yours.

DC Log is a dive logbook, dive planner and dive-safety app for iPhone and Mac, made by Māhanga Technologies Limited in Aotearoa New Zealand. This policy explains what DC Log does with your information.

No account, no server holding your logbook

DC Log has no sign-up and no account with us. Your dives, sites, gear, buddies, certification cards, dive plans, photos and settings are stored on your own devices. DC Log does create a random ID for each copy of the app, used only for the app activity described below; it is not an account and holds none of your logbook.

iCloud sync and backups

If you use sync, your logbook is copied between your devices through your own iCloud account (or a folder you choose, such as Dropbox). Backups are saved on your device and, if you turn it on, in your iCloud Drive. Apple stores this under your Apple Account. We cannot see it.

Dive Watch and your emergency contacts

The names and phone numbers of your emergency contacts stay on your iPhone. If you are not back from a dive by the time you set, DC Log texts the contacts you chose, from your own iPhone and through your mobile carrier, with your dive site and its location. These texts go only to the people you chose. Nothing is sent to us.

Location

DC Log uses your location only while Dive Watch is watching a dive: to put your position in the texts to your emergency contacts and to keep checking your return time while the phone is locked. Your location is not sent to us.

Camera, photos and microphone

• Camera and photos: used only when you choose to scan a certification card or add photos to a dive. The pictures stay on your device.
• Microphone and speech: used only when you choose to speak your feedback. Your words are turned into text by Apple's speech recognition (on your device where it can be), and you check the text before anything is sent.
• Bluetooth: used only to download dives from your dive computer.

Weather, tides and maps

To show a forecast, tides or sea conditions, DC Log sends the coordinates of the place you are looking at to Open-Meteo (open-meteo.com). On iPhone the maps come from Mapbox (mapbox.com), and on Mac from Apple Maps: the map asks them for the area you are looking at. DC Log turns off Mapbox's usage reporting; Mapbox still counts monthly users with an anonymous identifier, which is not linked to you. The weather map is Windy (windy.com), shown inside DC Log for the area you are looking at, with your dive sites drawn on it: the names and positions of your sites are handed to Windy's page in the app to draw them. No name, account or contact details are sent with any of these requests.

Feedback you send us

If you use the Feedback button, what you send (your message, any screenshots you attach, the diver name set in DC Log, and your device model and app version) comes to us so we can fix problems and improve DC Log. Your voice is turned into text by Apple's speech recognition, on your device where it can be; the recording is never sent to us. Nothing is sent until you press Submit. We use it for nothing else, and we delete it if you ask.

Purchases

DC Log is bought through the App Store. Apple handles payment; we never see your card or Apple Account details.

How we use app activity

DC Log tells us how the app is used, so we can improve it and run Māhanga's services: which screens and buttons are used, when a visit starts and how long it lasts, the app and device version, and daily counts such as how many dives, sites, gear items and dive plans your logbook has, and the countries you have dived. Each copy of DC Log has its own random ID for this, not linked to your name, email or Apple ID.

We never receive the content of your logbook: no dive details or notes, site or buddy names, positions, certification details, photos, voice or feedback text.

This information is stored by Māhanga Technologies on our own servers in New Zealand and with Cloudflare in Australia and New Zealand. We keep the click-by-click activity for 13 months and the daily totals for 3 years. It is never sold or shared with advertisers, and DC Log has no adverts and does no tracking across other apps or websites.

It is on unless you turn it off: Settings, Privacy, “Share how I use DC Log”. When it is off, DC Log sends none of this. To have what was already sent deleted, email us with the date you turned it off.

Children

DC Log is not directed at children under 13.

Your rights and contact

You can ask what information we hold about you (only feedback you have sent), ask us to correct or delete it, or ask a privacy question by emailing [email protected]. Māhanga Technologies Limited handles personal information under New Zealand law, including the Privacy Act 2020. You can also raise a concern with the Office of the Privacy Commissioner (privacy.org.nz).

Changes

If we change this policy we will update this page, and tell you in the app if the change matters.

Last updated 2 November 2026