ROLLING – what it is and how to face it

Rolling is that cyclic alternating movement on the longitudinal axis of a nautical vessel, whether under way or at anchor.

The causes

It can be caused by waves that reach the beam, by the wind, by an excess of height on the center of gravity of the load or by all these concomitant factors.

Pitching is mainly caused by the effect of the wave motion and only to a much lesser extent by the displacements of weights on board and by the interaction with other external forces, this due to the predominant inertia component to the longitudinal motions that characterises a marine vessel of conventional shapes. (i.e. elongated in the fore-aft direction).

More than pitching – which is the movement along the transverse axis – rolling is annoying for those who suffer from seasickness.

Rhibs, the solution for rolling

In general, the inflatable boats have little or no roll, because at speed the hydrodynamic support counteracts the oscillations and when stationary the aft terminals of the tubulars rest in the water preventing any movement.

On the more star-studded ribs, however, when the tubulars have a reduced diameter and are glued very high, the stabilizing effect is lacking when stationary and the rolling can become annoying almost like on a boat with a displacement round bottom.

Those who are sensitive to seasickness and are looking for a dinghy also for pleasant stops in the coves for sunbathing, will have to be careful to choose dinghies that are not too starry and with tubulars that rest firmly in the water.