UDDF stands for Universal Dive Data Format. It is an open XML format designed to move dive logs between applications, and it preserves the dive profile, gas mix and samples.

CSV is fine when you only need the summary data: date, depth, bottom time, gas. It does not carry the full profile, so UDDF is the better choice when it is available.

Which format does Depthlog import?

Depthlog imports UDDF, CSV and JSON. It also checks for duplicates, so importing the same file twice does not create double logs.

How to export dive logs to UDDF or CSV from any dive computer

The problem with dive log exports

Every dive computer brand has its own app, cable or cloud. Some export a universal format, some export a table, and some only show the data on screen. The result is a logbook that is hard to move, even though the data itself is simple.

This guide gives you one route that works across brands, plus a checklist to avoid the usual mistakes.

The universal route: Subsurface

Subsurface is a free, open-source dive log application that supports a wide range of computers. It can download dives from the device and export them to UDDF, which almost every logbook can read.

1. Install Subsurface

Download the version for your operating system from the official release page.

2. Download the dives

Connect the computer the way your model supports it: USB or Bluetooth. In Subsurface, open the import section, choose Dive Computer, select your manufacturer and start the download.

3. Export to UDDF

Select the dives, open the File menu and choose the export option. Save the file as UDDF.

4. Import into Depthlog

Open the Depthlog import page, choose the file and review the dives before confirming.

If your computer is not supported by Subsurface, check the manufacturer app for an export or share action. The target is still the same: UDDF, CSV or JSON.

UDDF or CSV?

Format	What it keeps	When to use it
UDDF	Profile, gas, samples, site and notes	Default choice
CSV	Summary rows: date, depth, time, gas	When the app only exports a table
JSON	Structured data from Depthlog or another tool	When you already have a Depthlog export

Pre-import checklist

Export all the dives you care about, not just the last trip.
Keep a copy of the original file before importing.
Check the date range and the number of dives.
Import in one pass if possible; Depthlog handles duplicates anyway.
After the import, open one dive and confirm the profile and gas mix.

Troubleshooting

The computer is not detected: check the cable or Bluetooth pairing, close other apps that may hold the device, and retry.
The download stops: keep the computer awake and download in smaller batches.
The file will not import: confirm it is UDDF, CSV or JSON, not a PDF or a proprietary backup.
Missing dives: check the export date range and repeat the export for the missing period.