The following six sentences come from a paragraph. The first and the last sentences are given. Choose the order in which the four sentences (PQRS) should appear to complete the paragraph.
S1 : One day I went into the water off the coast of Africa.
S6 : I hurled at him the rubber fins.
P : I sighted a shark at a short distance from me.
Q : He launched towards me as hard and swift as a missile.
R : I was floating at a shallow depth, without making a movement.
S : Every muscle of my body is tensed.
Select the correct sequence.