The Coriolis force killed a lot of people in 2005. It collected a deep pool of warm water that extended from the entrance of the Gulf of Mexico to quite a distance west of New Orleans. Hurricane Katrina passed through the pool and gained a lot of energy. The northern edge of the pool was close to New Orleans, so Katrina was still devastating when it got to New Orleans. A previous post, "Coriolis Force Puzzlement" had an explanation that would apply to an artillery shell going through thin air. On the other hand, an ocean current must flow through a body of water that is at rest with respect to the local rotating Earth reference frame. In the steady state, the path of the current is also at rest in the rotating coordinate system, but the water flowing along this path experiences a sidewise force equal to the Coriolis parameter f times the velocity times the density. Because of the current path constraint, the sidewise force does not produce a sidewise acceleration of the moving fluid. Instead, the force is balanced by a horizontal pressure gradient.
This horizontal pressure gradient shows up as a sea surface height gradient in the radar altimeter plots in the Gulf of Mexico Near Real Time Altimeter Data Viewer. Dynamic height contours are shown in 5 cm increments. They are closest together where the velocity is greatest. That's where the Loop Current is running. Note that the sea surface here is higher than the sea surface outside the Loop, but not as high as the surface in the interior of the warm pool.
So what was all that nonsense about the gravity-driven Loop Current descending down through the Gulf so that the hydrostatic force of the higher level outside the Loop pushed it together into a narrow hairpin shape. That was the raving of a confused Dick LaRosa. Ignore him, and let's see if we can get this right.