The submarining effect is caused especially by...
A)incorrect tyre pressure.
B)the consumption of alcohol and drugs.
C)improper use of the seatbelt or the vehicle seat.Correct
For the seatbelt to be effective and able to fulfil its assigned purpose, it must be of an approved type. It must be properly anchored, adjusted, and fitted to the body, and correctly fastened. A seat that is too reclined, or the use of cushions or inappropriate seat covers, can cause the occupant to slide under the belt (submarining effect).
Do not confuse this with the "tunnel effect", which occurs when peripheral vision is lost due to, for example, the consumption of alcohol or drugs.