Heinrichs Weikamp

Heinrichs Weikamp OSTC 2

An open-source technical computer with 6 programmable gases and induction charging.

Open BLE sync (libdivecomputer)

Syncs wirelessly with third-party apps (Subsurface, Currents, etc.), not just the manufacturer app.

Heinrichs Weikamp OSTC 2
3.6Comparison Score
$730
Released2015
Max depth rating120m
AlgorithmBühlmann ZHL-16C with optional gradient factors
Air integrationnone
Wirelessbluetooth
DisplayFull-color LCD IPS-TFT
Batteryrechargeable
Digital compassNo
Gas typesair, nitrox, trimix
Gas switches6
CCR capableYes

"Gas switches" is how many different mixes this computer can be programmed to switch between mid-dive, mostly relevant for technical/staged-decompression diving. It doesn't tell you which gas types (air, nitrox, trimix) are supported. See Gas types and the product description above for that.

Pros
  • Open-source firmware, divers can inspect or modify the decompression code
  • 6 programmable gases (nitrox, trimix, or heliox) across Air, Nitrox, OC Trimix, OC Bailout, Constant PO2 Deco, and Gauge/Apnea modes
  • Inductive (Qi) charging, no exposed charging contacts
Cons
  • Price converted from GBP list pricing, may not reflect current US retail
  • No wireless air integration on this base model (see OSTC 2 TR)
  • Niche brand with a smaller dive-shop support network than the majors
Diver community sentiment
Mixed opinions

Divers on Scubaboard generally praise the OSTC 2/2N's interface, bright screen, compact size and weight (notably smaller/lighter than a Shearwater Predator), and its feature set. Heinrichs Weikamp's customer service and repair turnaround are repeatedly singled out as a strength, with owners reporting fast, low-cost, and even out-of-warranty free repairs from the German factory. However, recurring reliability complaints surface too: button/screen failures over time, a depth sensor failure, a firmware date bug, and one long-time owner citing five failures across an OSTC 3 Plus and OSTC Sport before switching to Shearwater. Consensus leans toward a capable, well-supported, budget-friendlier Shearwater alternative, with inconsistent build reliability for some users.

Scubaboard: OSTC computers feedbackScubaboard: OSTC general discussion, page 3Michael McFadyen Scuba Diving: OSTC 2N vs Shearwater Predator

Summarized from public forum discussion (Scubaboard, Reddit, and similar), not a survey we ran ourselves. See the linked threads for the original conversations.

The OSTC 2 is Heinrichs Weikamp’s mid-range entry in its open-source technical computer line, offering 6-gas trimix and CCR support with a color display, aimed at divers who want full visibility into (and control over) their decompression algorithm.