the Sub · system
GPS doesn't work underwater, so she dead-reckons from motion, heading and depth, and zeroes the drift with a GPS fix each time she surfaces — with DVL bottom-lock and sonar/terrain matching stacking on for precision.
| GPS | SparkFun NEO-M9N breakout + antenna | Arrived |
| Compass | RM3100 magnetometer — received FlyArm Meg_3D_3100 (generic breakout, bare header) | Arrived |
| Depth primary | Bar30XT (BARXT-VP, sealed) | Arrived |
| Depth backup | Bar30 | Arrived |
| Camera primary | Arducam IMX678 4K STARVIS 2 USB 3.0 (bare module, NO enclosure) | Arrived |
| Camera secondary | DWE exploreHD (400m sealed, epoxy/potted cable) | Arrived |
| Iridium antenna feedthrough | SMA F-F bulkhead, epoxy-potted into M10 (depth-rated) + short internal SMA jumper | Arrived |
| Camera gimbal (pan/tilt) | Adafruit Mini Pan-Tilt bracket (#1967) + 2× MG90S metal-gear servos + printed camera adapter | Arrived |
| Camera rear | DWE exploreHD (400m sealed, epoxy/potted cable) — rear-facing | Arrived |
| I2C splitter | I2C splitter board (bundled with the Pixhawk 6C kit, #1) — passive JST-GH fan-out | Arrived |
| Lights | Lumen R4 set of 4 | Arrived |
| Echosounder | Ping2 sonar altimeter | Arrived |
| Lights — zone 2 | Lumen R4 pre-connected set of 4 (500m) — outer/wide zone | Arrived |
| Echosounder (forward) | Ping2 sonar — forward-facing (basic forward collision warning) | Arrived |
| Strobe (USCG) | Sirius Signal C-1003 SOS light | Arrived |
| Recovery pinger | DIY: piezo + ATtiny, potted | Planned |
| Pinger receiver | Directional 37.5kHz diver/locator hydrophone (topside) | Planned |
| Imaging sonar | Ping360 | Planned |
| Light sensor | TSL2591 lux (behind dome) | Arrived |
| DVL | Water Linked DVL A50 (300m) — 1-yr-old unit, 25% off | Arrived |