It will also reduce the amount of roll angle for any given force.
Which is the opposite of reducing roll, like you claimed originally.
I believe the intended point being made was that the retractable keel may have been raised to lessen potential snap rolling to increase overall creature comfort.
I see divers report the mast is still intact. More bodies have been recovered.
There seems to be some confusion over the effect of the drop keel. Anyone who has sailed on a bulk carrier in ballast will appreciate the effect a high GM has on comfort. When the drop keel with the bulb is lowered the centre of gravity moves down with it. The centre of buoyancy stays right where it is and the righting angle increases. Fishing at anchor in a slight sea is more pleasant in a fizz boat than a yacht . Super yachts with the passengers on board will typically sail during the day and anchor each night with the dinner table and the king sized bed being kept as motionless as possible from outside forces. Even fully raised the bulb still below the keel would provide a righting force sufficient in normal circumstances.
The paravanes present a flat plane to vertical movement through the water creating resistance and the length of the arm provides a lever thus damping the rolling. Sailing ships tried to avoid ballast passages but when it was unavoidable constructed wooden frames on deck to contain rocks and anything heavy to reduce the GM and prevent snap rolling with the resultant strain on the rigging.
Your diagram works for ships but not for yachts where the CG can be below the CB . Subs also like B to be above C when submerged.
the vessel had a lifting fin and bulb keel and the keel was up. this would have reduced stability in the vessel
ports were stated to be possibly open due to the hot weather and the vessel due to mast height went to one of her beam ends took on water through the open ports and sank.
yacht news present speculation
For large angles of inclination, rather than GM it’s simpler to use stability curves and righting arm.
It’d be useful to know the actual wind speed at the time.
From the builder:
“Following all the proper procedures, that boat is unsinkable .” …
Gee where have we heard that before?
I’d think it’s probable that, over a period of time, a yacht sailing in the Mediterranean would encounter very strong winds at some point.
Besides waterspouts there’s mirobursts and Siroccos, both of which can reach hurricane speeds.
Excuse me for not including the word rate as I did in the next post. I figured most people would understand that the rate of roll is what the passengers would find uncomfortable. I mistakenly thought most readers here are seafarers and would understand. Silly me.
“A marine engineer shouldn’t need to explain it (to) the deckies here but since it must be counterintuitive to some, lowering the heavy keel when there is no wind loading or weight of sails above the CG will induce a faster rate of roll that is very uncomfortable for most people. Raising the keel reduces GM and slows the rate which more people find acceptable even though the ship might be called “tender”.”
So Fort Schuyler gets to keep it’s name but we lose Fort Bragg? I protest. 
Still no explanation of how the water got in and sank her. More productive than roll comfort at anchor. We can presume an adequately stable ship regardless of the position of the drop keel.
Anyone?
Well,
IF rig/mast failure …
- mast portion pierces hull?
- chainplates ripped out?
-
rapid flooding!
IF the diver report of intact mast is true…
- open door/hatch/companionway?
- design?
-
rapid flooding
[e.g. stern platform open with its machinery space w/t door also open]
BUT, diver report of “intact mast” may mean intact within limits of turbidity & vis down there - in that area 5-10m. Until they check full length (good task for ROVs) who knows…
Then the final possibility…
… the Hewlett-Packard hit team from Elon’s vortex-generating spaceship 
But in general, getting tired of the media’s off-the-wall imagination from “eggspurts”, plus badly translated italian, being passed off as facts
Why can you assume that? Maybe that is not true.
One can only hope