Over the years we have learned a lot of things about diving that are seldom taught in training courses. One of the things we have learned from experience is that the conditions on the surface are not always indicative of conditions beneath the surface, and vice versa.
For example, on a day that is very windy and blustery, surface conditions can be problematic or even dangerous, while conditions a few meters below the surface may be completely calm. A brisk wind can turn the surface into a froth, generate choppy swells, and create or enhance surface currents. In short, the surface of the sea is not a pleasant place to be when it's very windy.
Most wind-driven waves and surface currents extend only a meter or two below the surface, thus as divers descend they are very likely to find calmer conditions. Our first tip, then, is to advise divers entering the water on a blustery day to descend as quickly as possible to get below the choppiness and surface current. Regardless of whether you're entering the water from the shore, or from a boat, if a strong wind is blowing and the surface is choppy, plan ahead of time to get below immediately and wait for your dive partner(s) there, not on the surface.
When divers are underwater on a blustery day, they can look up and see the wind whipping across the surface -- just like in the photo on this page (taken at Puako, Hawaii) -- and sometimes the wind actually can be heard from below, too. Our second blustery weather diving tip is this: If you look up and see that it is windy on the surface, try to surface as near to your boat or shoreline exit point as you possibly can. In blustery conditions, do not plan on making a surface swim at the end of your dive. Swimming through chop and swells will tire you, and if there is a surface current as well, it may carry you away from where you want to go.
In fact, when we dive in very windy conditions we consider the rough surface to be the equivalent of an 'overhead environment.' The term 'overhead environment' commonly refers to a situation in which there is literally a barrier overhead preventing the diver from making a direct ascent to the surface. The usual examples are diving in cave, or inside a shipwreck. In the case of extremely rough surface conditions the barrier is not a physical one in the same sense -- you won't bump your head on it! -- nevertheless, we plan the dive as if there were a physical barrier. We consider that a direct ascent to the surface in those conditions is not an option, and we plan the dive accordingly.
In summary, when the surface conditions are extremely rough, it is unwise (to put it mildly) to be on the surface anywhere but right beside your boat, or within wading distance of your shoreline exit point. Descend immediately when entering the water, and don't surface until you are right at your boat or your shoreline exit point.