wa... kayaking!! sounds so cool. but one thing abt it.. u'll be super tanned and tends to have drier skin..hmm.. but upon thinking that u'll have a more toned arm... hmm... WAHAHAHA! 5 hrs.. that's quite a long duration.
for toastmasters, u r right abt the part at building confidence in public. other than that i think it'll be quite boring =S so.. i tink.. kayaking would be a better choice. but most importantly is ur own interest in it la. so don't consider too much on my suggestion k? hee..