Finally a topic I can comment on
Having spent years working in a surf shop I have fitted out thousands of kids over the years and I agree with Spatacus. O'Neill suits and C-Skins suit are about the skinniest on the market and good value.
Originally Posted by spartacus
I go through the same scenario each year. I never buy new, it's simply not worth it. I've found O'Neill wetsuits are on the slim side. Check out Ebay - their 3:2 full length suits are decent quality and usually sell for what you paid for them after they outgrow them.
As already said get them second hand if you can, kids outgrown them before they can wear them out but fit is CRUCIAL. It doesn't matter how much it costs if it doesn't fit, it won't work. If you can try one on, do. All reputable surf shops stocks loads of the things and any worth their salt will offer a trade in service and second hand suits or if nothing else give you the size to go internet shopping.
As with anything there are loads of varients and brands available, some good many not so. I would stay well clear of supermarket suits, all that i have seen been made out of either rubber or very cheap neoprene with poor fit and no resale value.
Summer wetsuits are usually 3/2mm thick and are either flatlocked stitched or blindstitched, without boring the hell out of everyone, blindstitched suits are warmer for the same thickness but cost more.