Friday, 19 January 2024

Navigation in small open sailing boats

 I thought I'd pose the question on  a facebook forum where I am one of the admins

"How do people go about their navigation in a small open sailing boat?"


It provoked some interesting comments - not so much about the skills as what they use.

The majority of people seem to employ/carry the following:

  • Navionics app on smart phone (very popular)
  • Paper charts (less popular)
  • Chart plotter (fewer)
  • Some form of Garmin with either maps or charts
  • Tidal stream atlas and tide tables 
  • Handheld VHF radio
  • Depth sounder (odd one or two)
  • Binoculars
  • Handheld compass of some type 
  • AIS app on smartphone
  • OS maps app or paper map of area being cruised
  • Cruising guide
  • Breton Plotter and compass dividers (odd person or two)
People were less forthcoming about HOW they did their navigation but I deduced a couple of things from the comments. Firstly, in small cruising dinghies, a lot of people seem very dependent on electronic apps - smartphone based in the main. Quite a few would plot a position on a chart every hour or so as a back up. Many employed google earth/streetview/community photos to do their pre-passage planning. 

Secondly, it seems sensible to call it 'pilotage' rather than 'navigation'. I pondered this distinction for a while and I think it comes down to this - in a cruising dinghy you are rarely out of sight of land. Even when I cruise inshore I'm no more than three miles off shore at the most. Several times I was questioned about my carrying OS maps as well as charts and this surprised me. To be truthful, I often find the OS maps more useful than the charts for position finding. Mind you - OS maps don't show depths or pilotage buoys etc and that is of course invaluable. 



So, how do I do my small boat pilotage? I don't know this is the right way - but it is a way that works for me - although I'd love to hear anyone else's approach 

Pre trip - depending on where I am heading obviously, or how familiar I am with the waters, a combination of 
  • tides check
  • weather check - wind speed and direction, sea state, wave direction, air temp
  • tidal stream check and calculations - tidal streams/directions/drift for duration of voyage, gates and tidal range heights  
  • potential route plan ideas - Google Earth searches, streetview and community photos
  • waypoints entered into navionics and Garmin InReach
  • note buoys and lights on passage route
  • note all potential hazards on passage - marked on chart
  • check entry/exit requirements any harbours/ports calling in at  along with sailing advice
  • plan escape routes and potential escape anchorages
  • lights and annotated pilotage sketch maps if new area in little waterproof notebook
  • written passage plan summary - waypoints or markers, compass bearings marked on paper chart and/or in little notebook on the annotated sketch maps. 
  • contact details for various harbour masters etc 
On the day
  • weather information check against proposed passage plan - is it still feasible? 
  • passage plan copy left with someone along with ETA's etc
  • final check navionics and InReach waypoints 
  • InReach tracking page activated and test track messages sent to Wife and Daughter 
In the boat on the day
  • Check route progress on Navionics and/or chart and/or OS map
  • Enter a brief course, speed, estimated position note in log book every 30 mins
  • Plot a fixed point with time at position once an hour on paper chart
  • Ping an "OK" message every hour which goes from Garmin INReach to daughter and/or wife - it notes exact position and time and so gives them a regular update of my progress
  • weather apps check every three hours or so
What navigation skills do I use regularly and what do I rarely do? 
Regular use in boat
  • rules of road
  • lighting and buoys knowledge
  • basic chart and OS map interpretation
  • Compass bearings
  • plotting my position using a breton plotter viahree point fixes
  • measuring distances 
  • basic tidal stream interpretation 
  • transits
What I do very rarely 
  • tidal height calculations - if I ground, I ground - I'll float off at some stage 
  • estimated position plotting 
  • course to steer plotting/calculations
  • GPS plotting webs on my charts 


I did complete an RYA Day Skipper course about five years ago. It was really good and very informative. But, I've never mastered being able to do estimated positions on a chart in a 14 dinghy a mile off shore - without feeling sick; very sick! 

So, I haven't yet got majorly lost. I haven't hit anything! I have arrived later than expected on several occasions but through the Garmin INreach tracking mode and regular pinging of pre-messages - I can keep my wife and daughter update and they can see my progress on a  tracking map. I have grounded a few times - but up some of the rivers with their shifting sandbanks that is probably inevitable.  I've avoided most hazards thus far and have yet to seek shelter in an emergency anchorage. But that maybe because I rarely sail in weather conditions which might make that necessary - and that I guess is another discussion point for another time! 





3 comments:

  1. Thanks of this Steve, Really useful. Eisenhower said something like "Plans Are Worthless, But Planning Is Everything" which I think is sound.
    From what I read, your extensive pre-pilotage preparations lay all the groundwork so that on the day, the actual plan is held quite lightly and it can afford to be because the preparation lays a solid foundation.

    ReplyDelete
  2. Steve,
    Navigation includes pilotage.
    A passage plan is an international legal requirement.
    The plan includes pilotage (“eyeball navigation”) and passage making (out of sight).
    Your planning is definitely navigation, albeit entirely pilotage.
    John
    Cambridgeschoolofnavigation.co.uk

    ReplyDelete
  3. Hi John, thats a really good distinction I'd not come across before so thank you - really helpful.
    I'm sort of transferring some of my old mountaineering navigation skills I guess.

    ReplyDelete

Thanks for taking a look at my blog. All comments and advice are welcome - drop me a few lines. You can always find videos about Arwen at www.youtube.com/c/plymouthwelshboy. Look forward to hearing from you.
Steve