Sorry Kazz but someone who is self employed as yourself should be able to take a couple of hours off for a sail if you wish..
Or perhaps knock a day off a holiday??
Example, I dont go to Green Island etc which allows over a 10 day period.. 240 hours away from home. - Thats many 3 hour sessions i can spend and still be back to work.
Depends where you want to spend you sailing time

