Wayne.B wrote in
:

Anyone here have any experience with roll stabilization tanks -
designing, building, tuning, etc. ?

I'm talking about passive roll stabilization using port and starboard
water tanks connected by a "slosh" tunnel. If sized properly the
water sloshing between the tanks will be out of phase with the roll
period and dampen the motion, even at anchor.

Basically what you're talking about are "Flume" Stabilizers.
John J. McMullen (the company) was at one time the principal designer.
You might try going to them to see if they are still using them and if
there have been any advances.
No pumps are needed, other than for filling and installation; high up is
generally better for better results; you generally need to be aware of
stability (waddahey, you're basically making "free surface" work for you in
a positive way; the system works the same at all speeds, but EG you have
to roll for the system to work (sometimes that first roll can be a
doozy)..... etc.

otn