It's Easy!
J,Sailing with an infant is easy. When they get to be 18-24 months old, it's a lot tougher. We had our kids on board most weekends starting at the age of about 2 weeks. When they are young (less than 10-12 mos?), they don't walk. The same car seat you mentioned is perfect for the child. Fasten it somewhere below, and they will sleep for hours. The gentle rocking motion will also put the first mate to sleep! Once they start walking, their balance is not so good. Add to that the motion of the boat, and a football helmet should be required gear. On our 30 I built a gate for the V-berth. It looked like the side of a crib, with vertical slats. With lots of padding, the Vberth was great for napping, even under way. Once the kids started getting mobile, we found a safety harness with a 6' tether, fastened in back, attached to the binacle, much better than a hot bulky life jacket. Just some thoughts.Tom Soko