Sprucing up a cabin, advice please.

[prv]

I see in the pic the board with ON <number> RT <more numbers>. What do these mean?

Official Number xxxxx, Registered Tonnage yyyy zzzz/100 (ie yyyy.zzzz tons)

If you're registered on the Part One register then these numbers have to be displayed somewhere prominent and immovable. Traditionally they would have been carved into the main deck beam, but since boats don't have those any more they're generally on a plaque. But even then, the plaque is supposed to be fixed with tamper-proof screws.

Note that the tonnage figure is an archaic measure of volume and has nothing to do with weight.

Pete

 

[Cornish Puffin]

All good stuff, thank you very much people.