My late uncle, LIEUT. Roy L. Bird, R.N.R., served in Thunderbolt.
He's pictured in the Skull & Crossbones flag photo. He was responsible for navigation and they say that he had this incredible knack for dead-reckoning, always somehow getting them right where they needed to be, right when they needed to be there... apart from that, they say he spent most of his time sleeping!
After many successful sorties including a couple of special missions related to manned torpedoes, he was erroneously sent to the U.S.A. to collect a ship, otherwise he'd have been on board on her last fateful trip to the Med. No-one knows whether he would have made a difference, or would he have been killed too.
He did survive the War, to become Harbour Master in Singapore and eventually retired with his family to New Zealand.