SeaNav Autoroute

SeaNav “Autoroute” lets you quickly generate a route between end points based on depths and obstacles. Just set the start and end points and tap “autoroute”.

Most times these will match what an experienced navigator would manually place. Always check the suggested route for safety before following it. Autoroute is a planning tool and not a replacement for human judgement.

You can drag and drop waypoints to customise the generated route.
You can always tap autoroute again to have another go. Here is one we made earlier for a route from Portishead to Cardiff in the Bristol Channel. Spot on.


Sometimes autoroute can fail to find a route due to shallow depths, obstacles, narrow passages or even make a crazy route. Humans are still better than machines – thankfully. Moving the endpoints into deeper water, breaking the route down into shorter sections or moving the end points nearer together and re-tapping autoroute can solve this in most cases. If you are near the ICW on the East coast of the US, Autoroute will offer to use that.

Bridge narrows, lock entrances, and very tight tidal gates are places where chart data precision and autoroute resolution can conflict. The right approach is to place a manual waypoint at the exact gate/gap. autoroute then handles each open-water segment on either side.


Autoroute will ask for any missing charts for a route if you haven’t already downloaded them. This is a great way of making sure you have all the charts you need for offline use for a passage.



Please note:

  1. SeaNav autoroute is designed for open water routes and the Intracoastal Waterway (ICW) in the US. For the ICW we use Bobs423 ICW Tracks & Routes to help inform the routes. autoroute will not handle very narrow channels like canals & inland waterways.
  2. Routes can be shared and exchanged as GPX files for use with other Chart Plotters and by other SeaNav users.
  3. The SeaNav autoroute is based on the lowest astronomical tide. It does not take tides or tidal streams into account. Similarly SeaNav Autoroute does not look at weather or wind.
  4. As always, the captain takes full and sole responsibility for his vessel in using routes from SeaNav. Tides, weather, pilot guides and notes to navigation should be consulted.

Here is a step by step guide to creating a route including the ICW on the East coast of the US. Tap the route button at the bottom of the screen and select “New route”. You can also long press anywhere on the screen and tap “Start new route from here”. We are starting in open water but our destination is inland on the ICW.

Long Press on the chart to add the Start and end points for your route

Next tap “Auto Route”

In this case Autoroute cannot find an open sea route but it spots there is an ICW one so it offers the ICW tracks. Tap “Get Tracks for the ICW”. If you have previously done this, SeaNav Autoroute will automatically find the track for you without you having to go and get them again.

You will be taken to the SeaNav Bobs Tracks page. Scroll down to the link for the track for this section of the ICW. SeaNav will have automatically selected the correct track file for this route. If not you can browse the list of tracks via the link to Bobs Tracks download page.

The track will download and a Downloaded prompt will show at the bottom of the page. Tap Save and Save to files and then tap Open In

You will be shown a list of Apps to open the file with. SeaNav should be in the icon list – if not scroll to the right and select SeaNav after tapping More…Tap SeaNav

SeaNav will re-open and offer how to use the Bob’s track. Tap “Import as Track” (this is essential – you do not want a route created directly from the Bob’s track as this would have far too many waypoints).

The track will show on the map as a thin white dashed line – it will be the whole track from Norfolk to Southport. Next tap “Auto Route” again and SeaNav will use the track to guide the route.

Now you have a route

You can give the Route a name (type over Route2) if you want to now or edit it later via Manage Routes. Tap Done and you can now use the route. Tap the Sailboat icon bottom left to start sailing it.

You can hide the white track by tapping the Routes menu, Selecting Manage Tracks and turning off the Norfolk to Southport track. When you start sailing the route the SeaNav HUD will give you the distances and a continuous update ETA to your next waypoint and to the end of the route based on your current speed. You can also check the total length of the route via Manage routes.

SeaNav and an autonomous boat

Read about the latest development with SeaNav and the autonomous boat here

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 https://github.com/electricpocket/autopilot. 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…..here

Please contact help@pocketmariner.com 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.