SteerClear AIS
SteerClear AIS is the AIS assistant in the SWAY app. It looks at the AIS traffic around you, works out which vessels will come too close, and suggests a course that clears it, and keeps the wind direction in mind when you’re sailing.
How it works
1. Ahead or astern?
Your SWAY Breeze reads the AIS targets from your NMEA 2000 network. For every vessel it calculates how close you will pass (CPA) and when (TCPA), and whether you will cross ahead of its bow or pass behind its stern. Crossing ahead needs more room than passing astern, so SteerClear uses two safe distances: by default 1,000 m (about 0.5 nm) ahead and 250 m astern, plus the length of the other ship. You can change both in the AIS settings.
Crossing ahead of a ship needs more room than passing astern.
2. Too close? It suggests a better course.
When a vessel will come closer than the safe distance, tap Calculate advice. The Breeze checks headings all the way round and picks the smallest turn that clears it, for example “Steer 095°: 15° to starboard clears 1 vessel”.
3. Several vessels at once
With more than one vessel closing, SteerClear takes them all into one calculation and looks for one course that clears them all. If no course clears every vessel, it shows the best one and how many vessels are still too close.
4. It knows you are sailing
SteerClear uses the wind from your instruments. It never suggests a course in the no-go zone (by default 45° either side of the wind), so you get a course you can sail, for example on the other tack instead of straight into the wind.
The clearing course would be too close to the wind, so SteerClear suggests one on the other tack.
5. Under engine? Change your speed
When you are motoring, SteerClear also tells you which speed would clear the traffic, for example “Or slow to 4.3 kts”. Under sail you can’t really choose your speed, so then you go by the course advice.
6. See how it will unfold
Drag the time slider under the AIS map from Now to up to 20 minutes ahead. Every vessel moves along its course and speed to that moment. Your boat is shown twice: an outline where you will be on your current course, and a green one where you will be on the advised course, with the distance to the closest vessel. So you can see for yourself how the situation unfolds before you act.
The advice is for the moment you calculate it. It expires after 30 seconds or when your course changes, so you calculate again for where you are now.
Send it to your autopilot (beta)
With a Raymarine or B&G autopilot on NMEA 2000 you can tap Set autopilot. The app first shows the turn, for example “15° to starboard”, and only sets the course after you confirm. If the pilot is in wind mode, it tells you it will switch to auto first. Autopilot control is in beta.
What you need
- A SWAY Breeze with the latest firmware
- An AIS receiver or transponder on your NMEA 2000 network
- Wind and GPS data on the network (for course advice)
- SWAY Plus: €16,99 a year per Breeze, in the SWAY app
The AIS map and the list of vessels around you are free.
You stay in command
SteerClear advises. The skipper decides. SteerClear only sees vessels that send AIS, and the data and the calculation can be wrong. It is an aid to navigation: keep a proper lookout and follow the collision regulations (COLREGs). The skipper is always responsible.
How to use it: help page · Autopilot control · Live tracking · SWAY Plus FAQ · What’s new in SWAY 3.0