“accidental drowning is near certain to become the final autopsy determination, with alcohol or drugs as a possible contributing factor.”
He was an athlete and a decent swimmer. He was done in by drinking (weed?) then getting caught in strong currents while it was dark outside (my guess) His body was found where the currents are strong.
Oddly, most drowning victims know how to swim and are in good health. And drowning can happen suddenly and with little struggle when someone inhales water by accident.