36 metre dive in Red Sea

A planned 25 metre dive in the Red Sea at Marsa Alam, turns into a 36 metre dive during an AOW dive. Instructor insists that our 3 dive computers (Sunnto D4i x2 and Suunto Vyper Air) as well as both SPG's over read by 6 metres. Either way, my deepest dive to date, and found it very interesting. PS, yes breathing and air consumption were terrible, I know.