I agree with Warwick that swell direction and period combined with wind direction is very important, and that;s why I prefer the type of detail supplied by the surfing sites.
Very good example locally for me at the moment actually. We have 2.5-3 metre swells from the South but it is slow and barely a breath of wind, and the little wind there is, is just following the swell direction. In those circumstances, I have no problem going out it sea. The swell, although large, is slow and predictable and there is no wind chop at all. On the flip-side, if there was a significant cross wind or opposing wind, even 2 metre swells make you think very carefully before leaving land.