AS an ex-submariner I am well aware of the effects underwater sonar can have on divers and sea mammals.

Depending on the frequency range being used, it can, and is, used to deter sea mammals from certain highly sensitive areas of the sea used by the Ministry of Defence for military testing purposes.

This is in no wa, a practical explanation as to why the Redcar whale grounded itself – just my thoughts.

However, for the past couple of months, sea bed sonar surveys have been carried out daily from South Gare to the south of Redcar.

As stated in many of the reports, it is very unusual for a sperm whale to even enter the North Sea and for one to reach as far as the North-East coast is relatively unheard of.

Confused by so many relatively shallow areas it may have picked up the sonar signal and attempted to leave the area but managed to run aground instead – thereby sealing its fate.

Ray Vincent, Darlington.