Surface Markers and Lift Bags, oh my!
It's amazing how many names divers have come up with to define 'big floaty thing'.... One of the most common questions amongst new technical divers is trying to figure out the difference between a lift bag and a SMB (Surface Marker Buoy).
Lift Bags are typically used to lift large or heavy objects from underwater. Generally speaking, if you can pick it up without much change in your buoyancy, it doesn't need a lift bag, but if you need to grab your BC's inflator to pick it up, time for a lift bag. They can also be used to signal the surface of diver activities below, but in the ocean, waves can make it nearly impossible for a boat to spot a lift bag.
SMBs are used normally during deco hangs to indicate diver position to a boat, or in the ocean for signaling. They are typically long and skinny, compared to a 'short and fat' design of a lift bag.
Lift bags can be used in the event of loss of buoyancy as a redundant buoyancy device, provided they have a dump which can be used to expel gas during ascent.
Which one to carry depends on your application and location. Give us a call if you aren't sure which will work better for you, we'd be happy to help you get it right the first time!