Babies are so easy on a boat - it's when they get to be toddlers the fun starts! We live aboard our 28ft gaffer with our 2 kids
(age 2 and 11 months) and are bound for New Zealand
having left Britain in September. We've been living aboard
since July. My son (the 2 year old) did his first race
at 4 weeks old, and while not quite competent crew he's not far off now. My daughter doesn't know a different home.
My advice - don't think too hard about it, it's a whole lot easier than you think, kids
are so adaptable. Invest in child harnesses as soon as they can walk which gives them the ability to explore on their own on deck
with the safety
of being tied on but not the encumbrance of a full life-jacket. We use life-jackets in port and on pontoons etc, but when the boat is moving it's always harnessed on - certainly once they can move. When they are still immobile (and stunting their growth may be worth considering here....
) it's easy, just use their car seat as shown to great effect by an earlier poster. We lash the carseat in the cockpit
for our youngest and strap her in there when at sea. But she's just about to be introduced to her harness.
Another great piece of kit we have is a Bumbo seat - babies can sit in one from a couple of months old and it serves as high chair, play seat, can be in the cockpit
or wherever, is highly portable and made of rubber. Genius.
Enjoy - my babies love it so far.