Seafarers Tax

[Libellule77]

Hi

Does anyone know anything about Seafarers Tax ?
I know that if you are out of the UK for 183 days a year working on a ship, then you are eligible not to be taxed on your earnings, but want to know if this is per Tax Year (i.e April - April) or a period of 365 days from when you first leave the country. I have had conflicting advice from the Tax Office !

Thanks