A former commander in the Royal Navy and former senior member of staff at Coutts has been jailed for seven years and six months for indecently assaulting eight young men.
Charles Howeson, 68, used his "qualities, advantages and power" to act as a sexual predator towards young men while in three separate roles between 1985 and 1994.
He was convicted of 10 indecent assaults against eight young men during that period, following a trial at Bristol Crown Court last year.
The court heard he was the effective captain of HMS Cleopatra in 1985 and groped a junior member of crew on an unlit deck.
A Royal Navy inquiry was launched after the victim, and a second man who reported Howeson for touching his stomach and tugging at his shirt, complained.
Judge Mark Horton said senior officers associated with Howeson effectively closed ranks and put his interests, and the reputation of the Navy, "above those whom it should have been protecting".
Howeson was given a formal warning by the Royal Navy and never commanded a ship of the fleet again - though was promoted - and retired in 1990.
He then worked as a chief executive at a charity in Plymouth, where he indecently assaulted six volunteers in dark tunnels on Drake's Island and dark rooms.
Complaints were made but the allegations were not reported to police "to save the reputation of the trust", the judge said, and Howeson was allowed to resign.
Following his resignation, Howeson saw a further opportunity to "manipulate" and assault another young man.
The judge ordered Howeson, of Craigie Drive, Plymouth, to pay prosecution costs of £50,000 and sign the sex offenders register indefinitely.
"This case has revealed that to the outside world you displayed the finest qualities of diplomacy, charisma, endeavour, organisation and charm which you demonstrated during your period in the Navy and in your extensive and successful career and involvement at the very highest level with public bodies, authorities, businesses including a bank but also in your public and charitable works mainly associated with the community of Plymouth," the judge told Howeson.
"The hidden and dark truth is these same qualities were the very qualities which enabled you to mask and conceal a dark secret only revealed for the world to see some 30 years later in this trial.
"That secret was your uncontrolled and predatory sexual behaviour particularly towards young or at least vulnerable men under your control.
"Between 1985 and 1994, in three separate roles in your professional life, you used all of your qualities, advantages and power to use and abuse your position to enable you to act as a sexual predator.
"In most cases you effectively trapped them like prey in order to abuse them."
The judge said Howeson used his position and power to "plan and manipulate men" under his control in a persistent and planned way.
"None of these offences were opportunist," the judge said. "All were calculated and deliberate events."
Howeson had achieved the rank of lieutenant commander in the Royal Navy by 1985 but was the effective captain of the HMS Cleopatra and responsible for dealing with any complaints or breaches of discipline.
"Any refusal of any request or order by you would be a serious breach of discipline," the judge said.
After one man complained, Howeson began "grooming" his second victim and abused him while on an unlit upper sea deck.
The court heard the man struggled to fight Howeson off during the attack.
"He was only too aware that any refusal to obey your order or any act of violence against you to protect himself would have ended his career and almost certainly put him on a Naval criminal charge, the judge said.
An inquiry took place and Howeson was issued with a formal warning.
"Senior officers who were either directly or indirectly associated with you or that ship at that time effectively closed ranks, putting your interests and the reputation of the Navy above those whom it should have been protecting," the judge said.
Allegations that Howeson abused a second man on the ship did not form part of the criminal charges against him.
Howeson later abused men working at a charity in Plymouth which launched its own inquiry when complaints were made.
His offending was only reported to Devon and Cornwall Police in 2015.
Howeson denied all allegations against him but was convicted of the 10 charges following a trial in 2017. He was acquitted of two charges, relating to a ninth complainant, last week.
Representing Howeson, Daniel Janner QC said: "Until these convictions, Charles Howeson was widely respected and admired.
"He is deeply shamed and his life and public service had ended."
Mr Janner said Howeson, who is supported by his wife and family, had lost his 36 professional positions and faces personal bankruptcy.
Speaking after the case, Detective Sergeant Susanne Lee, of Devon and Cornwall Police, said Howeson's victims had been left with psychological harm for "many years".
"Now they have been through the additional trauma of going to court, however the result is that a sex offender has been brought to justice," she said.
"We wish to say thank you to those victims for coming forward and for being brave throughout this process."