: Is there any good reason to build a long slender Yost seaflea style
: boat as opposed to a shorter wider hull with greater initial
: stability for this application? I'm thinking scaled down
: recovery style with a very flat v. Almost like a whitewater
: boat.

: She's 15kg (30lb ish?)

Two big ones:

1. A long skinnier boat will be easier to tow behind you. Less drag. We mostly go out on a fairly large but sheltered pond up the road from our house.

2. A longer boat will also have more directional stability and will be easier to paddle in a straight line. If they can't paddle where they want to go they may get very discouraged with paddling in general. At that early age you want to make it as fun as possible.

My girls are 4-1/2 and 2-1/2 years old. I built them a small kayak when they were between one two years old. Both are my Coos 8 design (looks kinda like a Sea Flea): 8 ft long by 18 in wide. It tows nicely to about 3 knots and has plenty of initial stability. They named them the "Sharkbait" and the "Pink Pearl." They each started with outriggers. My 4 year old didn't need them on hers mid-way through the summer of 2009. She was 3-1/2. Now she's paddling hers just about any where she wants to and has outgrown the performance of the old "Sharkbait." It's seen some hard use...

http://clearstreamwood.com/WordPress/portfolio/kayaks/skin-on-frames/2007-sharkbait-coos-8-sof
http://clearstreamwood.com/WordPress/portfolio/kayaks/skin-on-frames/2009-pink-pearl-coos-8-sof

I'm building her a new boat this winter: 11-12 feet long and 15 inches wide. She should be paddling that boat until she's a pre-teen.