Here is something to get you started, although hopeflly someone will come up with a stronger answer.

I think the Knowsley is one of the boarding houses on the prom. Many of the boarding houses were named after towns in Lancashire. Many are now knocked down to make room for bigger hotels, apartments, banks and car parks.

Knowsley is, I think, on Loch Promenade. It is funny. You see things all your life, and then suddenly when you come to answer a question, you question your own knowledge, and think, I must go and have a look at that. Anyway a blue painted hotel springs to mind.

Whether your ancestor was staying there as a paying guest, or working there, I would not care to answer. Maybe someone else has firm ideas there.

As for boats: probably he was working on the pleasure boats in the bay: rowing boats and fishing boats = a tourist attraction. I have this in my family tree, but the term is boatman, in my case. This was an attraction still very popular in the 1950s but dwindled and eventually died out at a much later date (can't remember when, but Shimmin was the last to have the 'rowies').