infant sailing gear... wheee!
My hubby and I are both avid sailors, and we have a 4 year old and a 1 year old. I've got opinions about gear and safety for the teeny set.
* For an infant, the most important thing is a sturdy place to lash the carseat. Period. =) Between the issues of hypothermia and drowning, most infants are not ready to go into the drink, so a PFD isn't even really reasonable. Your next best option is just to keep them safe the same way you do in any other hurtling vehicle; in a car seat. Our youngest absolutely dug this.
* Once they're slightly older (more thermal mass and better swimming ability), PFDs are great, but you have to negotiate the tricky choice between comfort and materials. Kids should have non-inflatable (that is, foam) PFDs, but you also need to watch out for offgassing, which can be a problem. Salus, Lotus, and Astral all make fantastic non-offgassing seriously comfy PFDs for little kids.
* Obvee, netting on the lifelines is great, but only for after they're older, and understand the basic concepts of on-deck safety.
* We have harnesses and jacklines, but both boys get so incredibly tangled up that it's not feasible. I think that's for another, more mature, stage.
* Did I mention swimming? Swimming lessons are the #1 safety thing I'd recommend. There are infant swim lessons, or just free time at an adequately heated pool will do. Comfort in the water goes a long way towards comfort on the water.