Airmar DST810 Thruhull Install
Queen of Hearts had a basic standalone depth sounder wired directly to its display. It worked, but it sat outside the NMEA 2000 network and only measured depth. The goal was a single thruhull transducer that fed the whole network and added speed through water and water temperature alongside depth.
The Transducer
The Airmar DST810 is a plastic transducer body in a bronze thruhull fitting. It measures depth, speed through water, and water temperature, and outputs all three over NMEA 2000. One sensor, everything on the network.
| Model | Airmar DST810 |
|---|---|
| Thruhull fitting | Bronze |
| Transducer body | Plastic |
| Output | NMEA 2000 |
| Measures | Depth, speed through water, water temperature |
| Speed sensor | Paddlewheel |
The Displays
With the DST810 on the network, depth, speed, and temperature reach every instrument aboard. In the cockpit: a Furuno FI-50 (FI-503) digital instrument display, picked up used on eBay, gives a dedicated readout for each value without cluttering the chartplotter. Also in the cockpit, a Garmin GMI 20 pulls the same data from the network. Below, the Cortex makes the transducer data available over WiFi to mobile devices, where it shows up in Navionics alongside chart and AIS information.
| Furuno FI-50 (FI-503) | Cockpit, dedicated NMEA 2000 instrument display |
|---|---|
| Garmin GMI 20 | Cockpit, multi-function instrument display |
| Vesper Cortex | WiFi bridge to Navionics on mobile |
The Install
Queen of Hearts winters on the trailer, and spring haul-out time is when thruhull work gets done. The DST810 went into the same location as the old depth transducer, so no new holes were needed. The old transducer was pulled and the opening was cleaned of old bedding compound.
Old transducer out, opening exposed.
Old bedding cleaned from the opening before the new fitting goes in.
One difference with this model: the old transducer was a single unit installed from below the boat, but the DST810 works differently. The bronze housing goes through the hull, and the plastic transducer body is then inserted down into it from inside. A stringer needed slight trimming to allow enough clearance to drop the transducer into its housing. No changes to the hull itself.
The stringer was trimmed slightly to clear the transducer body going into its housing.
Bronze fitting seated in the hull.
The DST810 has worked well. The one maintenance item: the paddlewheel occasionally picks up weed or barnacle growth. A quick swim under the boat and spinning the wheel by hand is enough to free it up.