By Feras Dalatey, Jonathan Saul, Dmitry Zhdannikov, and Edward Carron, Reuters

Vessels seen anchored in the Strait of Hormuz.

Apache shot down by Iran on 9 June was involved in ship-to-ship transfer mission

Convoys sail dark with disabled transponders, spacing departures 3000-4000 meters apart

At least 116 ships have taken part since early May