<John wrote A flopper-stopper or two would have helped as well... not sure how to compare those to a tank for at-anchor roll reduction.> The key operative here was "simple is good". The roll stabilization tank works 100% of the time with NO effort on our part. Nothing to turn on, adjust, deploy, maintain, tune, setup or break down and store. By the way after 3 years I did open the access plates on top to check the water level. No water was required to be added! Dead simple! BTW, Swan Song is 58' on deck with a narrow beam of 12' 6" Dave & Nancy Swan Song Roughwater 58 Hawaii Passage '08/09