Bright lights

After yesterday's exertions and carousing I was rather tired so the fact it was a rather dull day at the office was quite welcome. A grey day, too; so I was easily lured by these bright lights on a big (ish) ship I could see from the Shore when I got off the bus. According to the ship AIS website it's a diving ship called the Mermaid Endurer.

How many mermaids can one ship endure during an average week?