What to look for in a shovel:
Remember, if someone is buried 3' down, you will need to move on average 1500- 2000 pounds of snow to uncover them.
Look for a large aluminum blade, extendable handle, tempered blade or shaft extending into the blade. D grips are nice, but they take up more room in packs and may not fit.
Many riders carry too small of a shovel. If you would not consider shoveling your driveway with it, why would you consider using it to dig for someone who's life depended on it?
In my opinion the Balck Diamond Deploy is not adequate to dig down 3' since it does not have an extendable shaft. They make the Transfer 7 shovel which is better. Other favorites include the Backcountry Access Companion Shovel and Voile with saw. Mike Duffy
Think of where you buy your shovel, do you want to support snowmobiling or buy from a retailer who is against motorized use in the backcountry.