I think both Thomson and Island cruises have a 'cruise only' option on their websites

http://www.mallorcaweb.com/directory/travel/travel-agencies/showAll/

This'll give you a list of 62 travel agents whom you could pop into depending where you are on the island. Good luck.

Island cruises are advertising last-minute cruises in the daily bulletin at the moment. You have to turn up at the port with cases packed ready to go, and only then do you find if you are going or not. Prices seem to start at €599 All inclusive for the week.

I have no idea if that is good value or not, but it seems a bit of a gamble.

Robin

Ocean village 2 are cruising from Palma, they do one week cruise only. Check out their site to see how much availability there is.

HTH
Biff

Thanks for all your suggestions. They are a great help.