In addition to using Olympic bar and plates, one can replicate traditional strength movements and exercises, while getting the stabilizing muscles and core deeper into the act.  Use it for dynamic warmup with low weight and work your core to the max!  Even with 3 gallons (~25 lbs.) of water (for a total weight of ~55 lbs.), you can get a core workout just staying on the bench, or keeping it steady overhead.

Steve Zabel, Inventor of THE WATER SLOG®

Empty weight is 30 pounds, and by adding water you increase the weight and the volatility of each rep.

The word SLOG in part means, long laborous work.  An arduous task.  That's what working out with THE WATER SLOG can feel like.  But each rep with THE WATER SLOG, even with lesser weight, will work your core and stabilizing muscles much better than iron weights.  That's because there's up to 16 gallons of water sloshing around inside (~165lbs. max).