It depends on wind direction and tide direction, swell and fetch. Also what speed you want to make good and how much sail you wish to carry or if you are just motoring or motor sailing. How many crew you have on board and their experience. Condition size and age of your Nauticat, on board equipment, standing and running gear is also a factor for consideration. I don’t wish to be sarcastic but this is not really the sort of question you should be asking of others. To be safe you should decide the limits based upon your own knowledge and experience etc. and if you have doubts about the passage and unsure about the forecasts don’t go. Wait until you are happy with more settled conditions.