Brunton has launched the All Day, a battery pack that attaches to the back of your Hero 3+ Go Pro and will extend battery life by up to four times more than the specified run-time.
Blurb says: "Brunton’s Go All-Day maintains the rugged, waterproofing your action camera requires"
Product page says: "Weatherproof Water Resistance (IPX5-Rated). Do not submerge."