Because of the strength of the water pressure out of the motor there is a lot of strength. If you do not have control over or is in the tank. You may agree more with rathaek.
Because of the force of the water pressure coming out of the motor is very strong. If you can not control or poised to address them. You may come crashing to the surface.
Because of the force of the water to push out of the motor is a very strength If you can not control or poised to live. You may fall and hit the water!