RedactedNarrative: Vessel 1, a PWC with only the owner/operator on board, was following behind an unknown 30-40 foot dive vessel.  Both vessels were traveling at an estimated 25 mph heading outbound towards the ocean in South Sound Creek.  PWC operator advised the wake from the unknown dive vessel pushed his PWC parallel to and up into the Mangrove trees that lined the channel.  As PWC went in to the trees the starboard side lifted up/port side leaned down causing operator to fall to his left landing on the Mangrove trees as the PWC came to a stop.  PWC operator dislocated his left shoulder and had puncture/lacerations from the trees on his right bicep and pinky. PWC operator said he was following and not trying to pass the unknown dive vessel when he got caught up in the wake of the dive vessel.  He could not pull away from the wake which pushed him into the Mangrove trees. 