Offshore banking can be for both current and savings accounts.
It really depends on why you would want an offshore bank account.
Not that I can advocate this but Swiss banks like UBS & Credit Suisse offer a fully confidential bank account which the UK - HMRC are unable to obtain details of if you have a significant amount of money to "hide away" from tax liabilities.
Many off the high street banks offer offshore banking facilities and belive it or not a huge amount of the worlds offshore banking takes place on the Isle of Man - Barclays amongst others have accounts based out of there.
If you move out to spain permanantly and sign off as a UK resident I can advise you on lots of tax efficient schemes with some of the worlds biggest institutions, dependant on what you want to achieve and the time frame.
I have a huge amount of experience in offshore financial services.
Mail me direct if you want any further info
paul.hackney@hgh-ltd.com