ITV News has been told that the squadrons have been working over-time and are having to cancel leave as they embark on back to back tours to Afghanistan and Libya.
The combination of stress and fatigue is potentially dangerous for those in charge of powerful fighter jets.
The causes of the crash are to be fully investigated in due course.
A vessel has gone out to the crash site to locate the wreckage ahead of a salvage operation.
More top news
Nearly 38,000 runners will hope to complete Sunday's London Marathon making it the biggest event in its 35-year history.
Rain across central Britain with longer, intense downpours with thunder in places this evening. A lucky few will stay sunny and dry.
Planning on going to the London Marathon tomorrow? Read our handy guide first!