I often wondered this and sorry for a bit of thread creep, many years ago Tomorrows World ( remember that) showed a triangular liferaft rather like a toblerone box in shape, the advantages were you entered from the end so it wouldn't tip over, and the triangular shape meant if it did tip, the sides became the floor etc... if that makes sense, was it ever developed?
They also did Chaff flares which made a lot of sense as you might not see the flare but the chaff would appear on a ship or coastguards radar.