I am curious to know whether the gambit of leading a fighter down into the sea or the ground with a more manoeuvrable aircraft has any credibility. Does this story ring a bell with anyone? Was this ever tried? I rather suspect that whoever dreamed it up did not have to try it himself!
Sunderlands used to hug the sea because it offered them protection, they were bristling with armament and were nicknamed the flying porcupines by the Germans, their one vulnerability was the lower hull.. So yes I could believe it.
The Sunderland was hit many times and some crew members were wounded but they managed to shoot down two, damage another and return home safely. Normal tactic for a Sunderland pilot when attacked by enemy fighters was to descend to water-level to protect the vulnerable hull from being riddled with holes and fight it out.
Your father sounds like he was a fine man.
Short Sunderland- The flying porcupine | Let Let Let - Warplanes