I'm currently working on, and am whittling away at problems
encountered, being able to access wifi from out in the harbor, without
having to be tied to an antenna - but there will still have to be some
gear up the mast, if I'm successful. However, that's only going to
work in range of some AP, most likely some household with an open
router, or a commercial pay site.
I have had success with a wl-330 as a repeater
http://uk.asus.com/products2.aspx?l1=12&l2=41
The wl-330 does not seem to be available here now in the UK ( I think
I had the last three!) The wl-330g is availble but it is not clear to
me that this model does wds. You probably need to use the ethernet
cable anyhow, if you are not repeating (wds) from an Asus device.