The finishing touch to each of the boy's ships was the "sail". We tried to think through all the advantages and disadvantages to the stereotypical sail design and decided that since we couldn't easily lower the sails if the wind was against us, we'd needed something that could accept the push from the wind in any direction OR be removed completely. Our solution? A balloon. We figured that since it was round it would catch the wind no matter which direction it was coming from and if the wind was counter-productive to our forward progress we could remove the balloon by popping it easily enough.
Our results? I will post pictures and a video from the actual race as soon as I am able!