As an occasional reader of Yachting Monthly "Confessions of the month", as well as from my professional background, I like to encourage learning from mistakes - both from others and my own.
I would like to start by sharing my confession that appeared in Jan-2021 issue of YM as a starter:
After an exhausting long day of hand-steering in 3+ meter seas from Visby, Gotland to Kalmar Sound, Sweden, we approached a combined marina and commercial harbor for a much-needed rest. It was around midnight, when suddenly our AIS VHF unit (not connected to chart plotter) gave an alarm of a vessel whose closest point of approach (CPA) was less than 0.2 nautical miles in 10 minutes.
Against the city lights in rain I could see a couple of big ships with lit decks. The tiny AIS screen on the VHF unit gave me the ship’s name and I promptly called them on VHF:
Fantasia, Fantasia, Fantasia, This is s/y Anniina.
Fantasia
We are progressing under sail, approaching you from bearing 095° and have CPA in 10 minutes in less than 0.2 nautical miles, do you see us on your radar?
Negative - we don't see you.
We are a progressing under sail and seem to be passing close.
For your information we are a tanker…
We concluded from their abrupt statement that they could not care less of us approaching so we followed their lights carefully and passed what seemed like safe distance while they appeared if not stationary, only travelling minimal speed. I later double-checked their AIS status and realized they had said:
We are at anchor.
With all the deck and city lights, it was next to impossible judge from lanterns whether they were anchored or motoring only slowly. Lesson learned - check also the AIS status message + integrate AIS display to plotter so you don't have to run back and forth between helm and chart table to add AIS targets to situational awareness when tired.
BR,
Tommi
s/y Anniina