Update: A salvage job in Mobile Bay last week changed my mind on using lift bags alone.
We were pulling up a small engine block in about 90 feet of water, and I had two 500-pound bags on it. The current picked up hard, and the whole thing started to spin like a top, almost hitting the hull. Three years ago on a calm lake job, I would have said bags are fine. Now I think you need a guide line to the surface no matter what, just to keep control. Anyone else run into this with a strong tidal pull?
You really had that much trouble with just an engine block? I've done plenty of bag lifts in current and yeah it spins a bit but it's not that hard to manage. A guide line is a lot of extra work for a simple job. Was the boat even in real danger or did it just look scary?