1. List is caused by Uneven distribution of weight within the ship. List will have the below conditions:
- GM is positive (GM > 0).
- The centre of gravity (G) is off-centre.
- The vessel is at equilibrium but inclines to one side due to uneven weight distribution, even without any external forces acting on it.
- The vessel rolls around the angle of list.
Correction:
- Redistribute the weight evenly to bring the centre of gravity (G) back in line with the centerline and metacentric height (M).
2. Loll is caused by High centre of gravity (G) leading to negative GM and is exacerbated by external forces, free surface effects, or poor distribution of weights. LOLL will have the below conditions:
- GM is negative (GM < 0).
- The centre of gravity (G) is on the centerline but too high, making the vessel inherently unstable.
- The vessel flops or inclines to one side at an angle of loll, and it can incline equally to either side.
- The vessel rolls unstably around the angle of loll.
Correction:
- Reduce the centre of gravity by ballasting bottom tanks or removing weight from higher levels.
- Minimize free surface effects by reducing the breadth of free surfaces in tanks.