Tanya, what is your skin type? Do you have darker pigmentation or very fair, etc? It makes a BIG difference on the effect of 5-FU on arms and legs. As I mentioned to you on an earlier note, my arms really had many AKs and I'm in my 50's, having worked in Florida sun, etc. Your cruise in April will be very close to treatment - 5 weeks post - and you will not be "healed" by then, so expect to have some scabs and tenderness still.
You are undurgoing a very intensive chemo treatment, and should follow your doctor's advice. I would not cut the treatment short just because of your vacation. You will not be eager to do this again soon, so be sure to complete the full length as directed. You are too far along to bail out, so best of luck and hopefully your side effects won't be too severe.
BTW, just today my scabs stopped bleeding and oozing - is that a word? But those who have been through 5-FU on arms/legs know what I'm saying. So in my case it took just about 5 weeks to get to the fist level of healed skin layers. What a ride! Hope the AKs are dead. Image of my arm last weekend, I started New Year's day.
http://i26.tinypic.com/34eep2o.jpg
Whitey