Several whistleblowers who served in the fleet told the Daily Mail they faced mistreatment from all ranks.

Adm Sir Ben Key, the First Sea Lord, called the claims "abhorrent", adding "sexual harassment has no place in the Royal Navy and will not be tolerated".

"Anyone who is found culpable will be held accountable," he said.

The allegations, revealed in detail by the Mail, include male crew members compiling a list setting out the order in which women would be assaulted in the event of a catastrophic event.

One woman told the Mail she was sexually assaulted by a man of a higher rank as she slept. She claimed one senior officer punched her in the kidney.

She alleged that another left naked pictures of models for her and posted 50p coins into her cabin, suggesting she would perform a sexual act in return.

Other women alleged they were frequently asked to perform sex acts and were often screamed at and hit with clipboards and pens.

It is claimed the abuse has been happening for more than a decade, after a ban on female recruits was lifted in 2011.

'Living in a parallel universe'

Louise - not her real name - spent several months at sea on board Royal Navy warships and says sexual harassment is rife in the navy because it is "normalised".

"It's like they're all living in a parallel universe out there," she tells the BBC.

"The night before they hit shore - unless they are on duty - they drink ridiculous amounts."

Louise, who is in her 40s, sees alcohol as a key trigger to the unacceptable behaviour she experienced during her stints on board two ships in 2019 and 2020.

She told the BBC about one occasion, in 2019, when an officer stuck his hand up her skirt while they were drinking in the Officer's Mess.

When she protested and put a stop to things by announcing she was returning to her cabin, the officer followed her to her room.

"He thought me going to bed was an invitation," she says.

"He hammered on my door, condom in hand. He wouldn't take no for an answer."

Even the morning after - having eventually given up his pursuit - there was no apology forthcoming: "He thought it was totally normal behaviour."

The Ministry of Defence has been contacted about Louise's allegations, but is yet to respond. The incident was not reported at the time.

"I worry about these boys," says Louise. "It's not their fault if they are told this is normal. It's a culture. No one above them is setting an example."

"The Navy needs to wake up and realise this is not the way the world operates."

Former Navy Rear Adm Chris Parry told the BBC's Today programme he believed the issue was also a reflection of wider society.

"I'm afraid some of the sexualised behaviour that we see in the normal working place is transferred to submarines, as you would expect, and of course in a compressed environment everything becomes exaggerated," he said.

He said the issue requires leadership, including "zero tolerance from the top down and the bottom up" when it comes to accusations of sexual harassment.

He added that when he commanded ships with a mix of genders he took "very seriously" accusations of assault.

Emma Norton, from charity the Centre for Military Justice, said any investigation would still involve "the Royal Navy investigating the Royal Navy".

"What a lot of campaigners and service women have been calling for many, many years, is for those responsible for investigating serious complaints like this to be taken away from the single services and handed to an independent body," she said.

'Totally unacceptable'

The Submarine Service is "unseen and unhindered," according to the Ministry of Defence (MoD) website, which says it has "built an enduring reputation for professionalism and courage".

The service includes the Vanguard Class submarines that provide the UK's nuclear deterrent.

Figures revealed in a Freedom of Information (FOI) request showed that, as of 2019, just 1% of Submarine Service personnel was female.

Responding to the allegations, Adm Sir Ben said: "I want to reassure our people, and anyone who is reading this, that any activity which falls short of the highest of standards the Royal Navy sets itself is totally unacceptable and not a true reflection of what service life should be.

"These allegations are abhorrent. Sexual assault and harassment has no place in the Royal Navy and will not be tolerated."

The MoD said that while most navy staff enjoy rewarding careers, some personnel, predominantly women, have been affected by inappropriate sexualised behaviour.

It said it accepted more needs to be done to improve the experience of all personnel and mechanisms for reporting sexual offences were being improved.

The whistleblower who told the Mail she was sexually assaulted by a man of a higher rank as she slept no longer serves in the navy. She was dismissed from service over a separate incident and given a suspended prison sentence for disclosing classified information that compromised security.

In 2019, the Ministry of Defence published a detailed report on inappropriate behaviour that included dozens of recommendations on how to tackle the issue. This included improving the complaints system and processes, encouraging more complaints, and dealing with them better when they occur.

"Ultimately, however, the challenge of inappropriate behaviour can only be addressed through a determined effort across the whole force to change the culture, driven persistently from the top," the report said.

Earlier this year, media reports emerged detailing allegations of bullying, drinking, misogyny and sexual harassment in the Red Arrows.

A series of incidents within the flagship aerial display team prompted the Chief of the Air Staff to order an inquiry, which has yet to report.

Last year, Diane Allen, a retired lieutenant colonel from the British Army, said the military needed its own Me Too moment, referring to the movement which saw people share their experiences of sexual harassment.