If you already have a bank account it won't be a problem unless they have to correspond via letter with forms etc. You will just have a problem if you wish to open a new account at any time. You could move off the boat and stay with a friend for a month when your passport needs renewing, I guess a representative address would work for your driving license as they would just need have contact with someone who will know where to find you if you are a bad boy <img src="{SMILIES_PATH}/wink.gif" alt="

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A PCMCIA card looks like this and fits nearly all laptops except the most recent.

T-Mobile provide it free if you sign up for 18 months. Or if you have one of the latest laptops with no PCMCIA slot they do a USB device.

Your old router will be redundant.
The best aerial is probably this one.
The Web site is here
http://www.wilsonelectronics.com/ViewProductB.php?ID=2It's the one I use, I had it shipped from the USA for $60, which was cheaper than I could find it in the UK.
For Web browsing and emails you'd need to be on the Web for several hours a day all month to use 3Gb of data transfer, It would only become a problem if you regularly downloaded music, video or large programs. I run my Web sites do all my email, and loads more and I've never gone over 3Gb.
UMTS is: (
Universal Mobile Telecommunications System) a broadband, packet-based transmission of text, digitized voice, video, and multimedia at data rates up to and possibly higher than 2 megabits per second.
I think you will find that the post code for your insurance is only applicable to where the vehicle kept. So if you were to keep it at a friends house then using that post code would be OK as it would spend most of its unused time there, and where you drive in the UK is none of there business. You should be able to give the boat as the place your MC is kept as it's damn near impossible to steal one off a boat.