My self and my wife were in a compromising situation on Slocan Lake in BC last Summer. She capsised. I rescued her and we derifted to a beach rafted up in 25 mile an hour gust. We were stuck there for 3.5 hours till the wind subsided.When we left to cross the lake it was 85 degrees and the lake was like glass! 45 minutes later on the other side it all changed! We had no flares (stupid!) Only the worlds loudest whistle :-) ! Really! But it only works for a minimal distance. We saw 3 boats but no one saw us! Its a mile and a half across this lake and it has very little boat traffic. Great for kayaking but lousy for hitching a ride! So I decided that along with my other rescue eqipment I carry, both my wife and I carry these signal mirrors. Simple and very effective up to miles away. Remember even that great Summer morning paddle to the otherside of the lake can change very quickly into a gotta be helped situation. Just saying from experience be prepared. These mirrors ar cheap and available on the net.