SeaNav and an autonomous boat

We have downsized the Pocket Mariner test boat from a catamaran cruiser to a catamaran dinghy (Dart 18) and are doing our bit for Net Zero and our ears with an electric outboard.

We chose the Torqeedo 1103C which has slightly more power than an e-Propulsion and also had the benefit of being available rather than on a 6 month back order. It is a revolution compared to a petrol outboard. Totally silent apart from the sound of water flowing past the hull, instant start, no oil or smelly petrol and fumes. A real joy, here is it in action on the river Wye:-

As well as using the test boat for testing our marine navigation apps we got inspired to take the boat to the next level and see if we could automate it and ultimately use SeaNav to control it to follow a SeaNav route.

Two steps:-

  1. A bluetooth LE enabled autohelm attachment to control the outboard direction
  2. Add the bluetooth driver capability to SeaNav and get it to maintain course and change course at Waypoints.

A possible 3rd step is to add a remote throttle control too so we can go fully autonomous!

This article covers step 1.

Step 1. Bluetooth iOS remote for Navico TP5000

Autohelm units are very expensive ( over £400) and none offer remote bluetooth control. We couldn’t find one that supported remote NMEA0183 control either. So we bought a second hand Navico TP5000 unit off eBay and adapted it to support Bluetooth using an Arduino BLE nano33 board and 3 relays attached inside the housing to the switches. The project design, instructions and code is here This could also be adapted to control a Raymarine Autohelm unit.

Here is the Navico TP5000 in manual mode attached to the boat and Torqeedo outboard:-

and here is the TP50000 controlled with our iPhone autopilot app:-

Next is to test this on the water and then move on to Step 2…..

Please contact if you have any questions or suggestions.

Tidal Streams for SeaNav

You can now view the current and predicted tidal flow rates and directions live on SeaNav’s UK and IE vector charts.

We use the official chart Tidal diamond symbol, rotating it to point in the flow direction. Blue means the rate is decreasing, red and its increasing. The diamonds update in real time on the chart. For planning tap on a tidal diamond to see the rate and direction, tap i for more information and see the rate and direction for the next 3 days on a graph at the bottom of the screen. Slide the time cursor ( or just tap at the time you want ) and all the tidal diamonds in view on the chart update as you adjust it (not just the one you have selected). You can zoom in and out of the graph timeline using pinch gestures. The Tidal Stream information is cached for up to 7 days so will work when you are out. of internet coverage as well.

The new Tidal Stream feature requires SeaNav 5.3 or later and uses official data from the UK Hydrographic Office, updated annually. A current UK & IE chart subscription is required to view the data. We hope to add Tidal Streams for other areas where available if they prove popular ( FR, NL & BE, DE… ). Please email us and let us know.