When I was doing this in other people's boats, the primary concern was taking all the spares you need. We had a fantastic workshop with every tool, screw, etc... you would ever need, fully stocked at all times. Also, second on the list was usually food
. Everyone has their one favorite snack (Dr. Who had his jelly babies - lol). I found that provisioning
up WELL at the natural foods store (Whole Foods) in Ft Lauderdale before heading into the Caribbean
was one of the best things to do. Not that we didn't eat a ton of great local produce (mangoes, avacados, Dr. Seimer's juice drinks), but having those few little items from home helps you keep your head
about you if things get a little crazy.
We also stocked up on sunblock, saline solution and little odds and ends like that. Wasn't 100% necessary, unless you demand a certain brand.
Best to stock up on any prescription meds in a *different* country since meds in the States are overpriced (don't know about the UK's prices).
Just a few things, from a larger boat perspective. Many of the same ideas apply to our sailboats.