I think it was every 10 seconds, because the barge was slow, about 4 to 5 knots, if I remember correctly. Btw, interesting to see that OSMAnd changed the speed unit to knots automatically.

Maybe they can be put in a master relation, because that route in Cornwall looks similar to the one on the official website.

@myozone: The GoPro Max does that automatically, even though it’s a few meters off.

Thanks very much! I hope I won’t ever need to follow these instructions, but it’s good to have them.