collision course - Tip
heres a little tip i learned a long time ago from a teacher while i did a basic beginners sailing course,ive done other more advanced courses since then but never heard this tip since, in any of the latter courses.
its only applicable for sailing in lakes,rivers ,harbours.
if you think your on a collision with another vessel,look at the land behind the other vessel,if the vessel is moving forward in relation to the land behind it,it''ll pass in front of you.
if it appears it''s going backwards in relation to the land behind it(you know the vessel is actually going forward),it''ll pass behind you.
if it appears to be staying stationary in relation to the land behind it,your on a collision course.
just a quick method that takes only seconds,of course this method assumes both vessel holds its course & speed,both of which can change at any time.