Most inflatables are design cathegory rated as "C". This is Beaufort wind 6 and 2 meter waves. I believe this is a contradiction as Beaufort 6 means "big waves dangerous for small ships", so I guess that rate is to let them be sold as "safety boats for bigger ships".
The closer to the coast, the more dangerous is the sea. Breaking waves can make you capsize. Water inside will make your boat heavier and slower (even though, a little water will make it more stable).
When looking for a shelter you have to govern against wind and waves: so you need a good engine, but you cannot full open throttle it for top speed. Waves must be passed by on a diagonal direction.
If you govern on favour of wind and waves, in the best case you will end up in a beach with 2 meter breaking waves.
My boat is 4 meters 20hp. I never go boating when wind is stronger than 16 knots.
I always check both windguru and local forecast (Agencia Estatal de Meteorología - AEMET. Gobierno de España
in Spain for maps) for wind speed, waves height and wind direction, and also hour of the day as a nice morning can be a horrible afternoon. My internet mobile phone is perfect for planning: and my family and friends know that it is not me who decides to go boating, but weather does.
When I see a little foam on top of inside sea waves (such as "small sheep"), that makes me think of beer, so I better govern my boat to the pub...