How to import dives from a Heinrichs Weikamp dive computer

Worth knowing

• Heinrichs Weikamp publishes no logbook or dive-import software of its own. OSTC Companion, the only desktop tool it ships, does firmware updates, clock setting and custom text only. Getting dives into a file is delegated entirely to third-party software.
• Every OSTC manual still tells you to visit Service then Software on www.heinrichsweikamp.com for the list of compatible logbook programs. That page is gone: the domain now redirects to hwdiving.com and the new site has no software page at all (its full page sitemap contains only shop, hwOS, firmwares, FAQ, manuals and legal pages). The printed instruction is a dead end.
• The single OSTC_Companion.zip contains three installers: OSTC_Companion_3.2_1.exe and OSTC_Companion_3.0_8.exe for Windows, plus OSTC_Companion_3.0_8.pkg for macOS. The macOS build trails the Windows one by a version. All three are dated October 2025, so the tool is current.
• The brand splits cleanly in two for connectivity. Cable generation: OSTC 1, OSTC Mk.2, OSTC 2N, OSTC 2C, all USB with an FTDI chip. Bluetooth generation: OSTC 2, OSTC 2 TR, OSTC 3, OSTC plus, OSTC sport, OSTC nano, OSTC cR, OSTC 4, OSTC 5. The cR additionally has an S8 bulkhead connector for rebreather sensors, which is not a data port.
• Firmware families map to models as follows: hwOS4 covers OSTC 4 and OSTC 5; hwOS Sport covers OSTC sport, plus, 2, 2 TR and nano; hwOS Tech covers OSTC 3, 2, 2 TR, cR, plus and nano; the separate mk2 firmware covers OSTC 2C, 2N and Mk.2. The DR5 rebreather controller has its own firmware line.
• No special USB driver is needed for the Bluetooth models. Both the hwOS and hwOS4 manuals state plainly that pairing creates a virtual COM port and no driver is required; you only have to select the right outgoing SPP port in the software.
• For the old FTDI-based units, the FTDI virtual COM port driver is required on Windows. FTDI's own download site blocks automated requests, so no direct driver URL is listed here; Windows Update normally installs it automatically, and users on the HW forum report reinstalling it by hand when a Windows update strips it.
• iOS never lists the OSTC in the system Bluetooth screen. Connection happens inside the app (Subsurface Mobile or OSTConf). Early OSTC sport units with red buttons are Bluetooth 2.0 only and cannot talk to iOS at all.
• HWOS Config (Android) and OSTConf (iOS) are community-built apps, not Heinrichs Weikamp products, but the official manuals and FAQ recommend both by name as the easiest way to update firmware. Neither downloads dives.
• The official English site is reached with a language query parameter (hwdiving.com/firmware/?lang=en, /manuals/?lang=en, /faq/?lang=en). The unsuffixed paths are German and use different slugs (/firmwares/, /anleitungen/), so the English and German URLs are not simple mirrors of each other.
• Some manuals are German-only. The hw Video, hw Backup, hw 40 and the 2026 catalogue PDFs are served from the English page but are the German documents; the RSU and OXY S3NS0R manuals are bilingual.