180 nm on my 29.5..
..that what it takes to sail from Tel-Aviv , Israel to Larnaca , Cyprus ,one way , all of it open unprotected waters , with often changing weather , a lot of motoring , or head winds ; not strong but enough to make it often not a smooth passage. once , in a rally , we were caught in 35-45 kts ( fortunately from the back) and 3m waves , just the last 5 hours before entering Larnaca marina. with just a piece of jib , and fighting the rolling ( a deeper fin than the 4' will probably fare better), we were doing 6+ kts,but at no time then , and in other cases , were we in danger , or felt the boat limiting us ( again, except the shallow fin , not so good for tracking a course , beating or running.. unless calm no waves condition).Such leg (180 nm) takes us about 33-36 hours.I did it so far 4 times in last 6 years , as due to local geopolitics , there is actually no other off-shore trip to take from here , if one want a change to several hours/coastal sail.The thing that makes or breaks such trips , assuming the boat is ready and prepared is 1.experienced crew or 2 at least 2. happy crew..fortunatelly , I have both. I will continue doing it ; it is an experience ,it's a chalange , it's away from the rat race,and the greek food and Ouzo in Cyprus, is great to share with good friends..