Have a play with this site
http://www.shipais.com/

Looking at the bristol area...
http://www.shipais.com/showship.php?mmsi=304010625

Two tugs in Portbury docks - Thorngarth and Portgarth

Click on Portgarth and it info appears on the left hand side - its 30m long - at 148th that's 20.2cm
Click on Thorngarth - that's 33m - 22.3cms at 148th scale

you can also find your fishing boats on there.

looking of plymouth...

24m trawler louisa N...
http://www.shipais.com/showship.php?mmsi=235008741

Lots to play with enjoy!

Russ

Thanks guys,

Sorry but forgot to say that the layout is set on the Mediterranean coast (normally bore everyone with that bit).

Thought the japanese boats would look OK.

Might put new thread on the japanese thing to find the length as if longer than 5/6 cm it'll be difficult to fit them in.

Thanks again weave