There is no age to get closer to the world of sailing, we had boat a child of seven months and a girl that her first week of charter did it at the age of 1 year and from there no longer stopped. The boat children enjoy a lot and with proper care can lead you on a cruise even from very small. If you opt for accommodation in boarding the cab was a little more tied, because you have to choose a time when there is another family with children, so you do not become bored and maybe not disturb the rest of 'crew. If you choose to rent a boat in autonomy or in bareboat or yacht with skipper, will the children to give rhythm to your holiday and are not sure how often they want to believe to stop you from making sailing holiday. Surely if quand take them by boat to swim already know or at least have no fear of the water they will enjoy more and you're probably more relaxed.