 In the case of sidemount, the two cylinders can be carried separately, distributing load and making transport on rough ground easier.Sidemount divers generally have more options available for donning and doffing than backmount divers, since they can choose to don or doff their single or double cylinders either on the surface or while in the water, depending on preference and conditions.Individual cylinders can be passed to and from a boat crew or a buddy on shore who is not burdened by gear, or lowered and raised by a line.