There is no minimum age, but no doubt children's needs vary and with them the precautions to be taken. 

Babies up to at least one year old do not walk, so the boat presents little danger; once their feeding and napping routines are respected, they will be lulled by the sea in their carrier all day long! 

More critical is the age at which children move around; they are curious about everything and do not always listen to their parents. From ages 6-7 onward everything becomes easier and more fun!

If you are thinking of a sailing vacation with children, choose if possible boats with a large, well-shaded cockpit, perhaps with two bathrooms and a comfortable dinette. The spacious and stable catamaran and gulet are always a good option.

If you are thinking of a touring vacation with your children, avoiding the peak season might be a wise decision so that you can decide from day to day whether to return to port in the evening or enjoy nights at anchor when the sea is calm. During the peak season, in fact, especially in some destinations, it is necessary to reserve a berth in port in advance.

Windbreakers to protect themselves during windy days, a hat, sunglasses, sunscreen and light-colored T-shirts to wear even in case of sunburn. Best to have pyjamas for cooler nights and a hoodie. Reef booties will come in handy on several occasions, and then the necessities for experiencing the sea: mask, fins, mat, if armrests are needed. If there is any food or product that your children just can't do without, better take it with you so you don't go crazy doing galley in the harbours!