Current Sea Conditions question

Can someone tell me how wd comes up with the current sea conditions. Today we had a westerly wind gusting to 25-30 mph and the sea condition showed as a ‘moderate sea’ however when we went for a walk along the promenade today it was anything but a moderate sea. You see I live on the eastern tip of Kent in the UK and our prom faces SE with 100ft cliffs and the sea state was almost flat with slight ripples and a bit of swell (and this was at high tide). If this had been a different wind direction, say NE or E or SE we would likely had more than a moderate sea!

As Broadstairs is a day tourist place most people would be interested in the sea conditions close in shore and not in open sea, am I shooting myself in the foot by using this on my website? Is this supposed to be a sea state in open sea, so that here in the English Channel it would not be appropriate?