Notamplot -
http://www.notamplot.com/ or
http://www.notamplot.flyer.co.uk/
Haven't tried the "Notam Plot" site mainly 'cos I'm fairly interested in stuff happening out to sea and a programme optimised for gliders shouldn't be too good at that.
Not sure why you'd say it doesn't work out to sea, and I don't know about the gliders connection, but I use it routinely and find it excellent. I also read the AIS stuff online just to double-check.
Andy