If you are so concerned with kids starting it on accident then just put the boat in gear after you kill it. it wont start in gear so unless the child has enough awareness to more the throttle to neutral and then push the button or turn the key but if they know to do all that then you are screwed either way.

i know whats coming next "what if the safety switch doesnt work and it gets fire up in gear and runs people over" not likely but i guess a valid concern?

im with KG, i know alot of people on here are paranoid about the liability issue of someone coming in contact with a prop while swimming with the engine running but have any of you actually tried to touch the prop while you boat is in the water? i got a rope tangled in mine in the middle of the lake last spring and trust me, you are not going to accidentally hit the prop while swimming. that sucker is far under there