When Oxana's sailor father left his home in Crimea's Black Sea port of Sevastopol in September, he just said he would be going to "the Mediterranean Sea".

But the family soon realised the true purpose of his mission -- Russia's military operation in Syria.

"They sent a bunch of ships from Sevastopol and everyone they could find to make up the crews," said Oxana, who agreed to speak to AFP on condition her family name not be published to protect her father.

Before he left, Oxana's father -- a retired navy officer -- was working on a vessel providing logistic support for Russia's Black Sea fleet.

While he is not saying much during phone calls home about his latest mission or how long he will be away, she is convinced that he is now onboard a ship backing up Moscow's intervention in Syria.

"My father knows when he will be back but he is not saying, he can't," Oxana said.

"It was thought that it would be a few months but it's already clear that this would go until the New Year and may last longer," she said.

"He calls from a satellite phone, tells us nothing, all their conversations are recorded."

Oxana said she was not worried for her father's safety as he was not planning to go on shore but felt indignant, accusing the authorities of exploiting his sense of patriotism.

"My mom said recently that his latest salary had been transferred to his account -- less than 10,000 rubles ($156)."

"They are using them any way they want and he thinks he needs to be there for the sake of Russia, out of a sense of patriotism."

On September 30, Russia launched a bombing campaign in Syria, saying it needed to target Islamic State jihadists, but the West has accused Moscow of seeking to prop up the regime of Bashar al-Assad and hitting moderate rebels.

Moscow has not publicly put a timeframe on its campaign in Syria.

- Secret Soviet-era Syria mission -

There is one other reason why Oxana believes her father was sent to help the mission in Syria -- she suspects he was already sent there back in the 1980s as part of a secret Soviet deployment.

"Those who remember our first Syrian campaign, from the Soviet era, are especially in demand," she said.

After Israel invaded Lebanon in 1982 and chased Syrian troops from Beirut, the Soviet Union sent several thousand troops to prop up Damascus.

The 1983 intervention -- dubbed Caucasus-2 milliary drills -- was shrouded in secrecy and set in motion after Syrian leader Hafez al-Assad, the father of Bashar al-Assad, came to Russia for talks with Soviet leader Leonid Brezhnev.

The young woman said she believes her father was on a mission in Syria in the 1980s -- "before I was born" -- although he never directly confirmed this.

Another Sevastopol-based source, who knows some of those who served in Syria in the 1980s, said they are still reluctant to talk about the Soviet-era mission.

"Many did not even tell their families what they got their awards for," she told AFP on condition her first and last names not be published because she was not authorised to speak on the matter.

The new generation of Russian servicemen are equally reluctant to publicise their role in the current intervention, she said, estimating that more than 1,000 people have been sent to Syria from Sevastopol including marines.

The source, whose son used to serve in the army, said the servicemen had been promised in August that they would be rotated.

"Three months there, two months at home," she said.

"They were told that they would now be going to Syria regularly. Those who believe that their families will not survive so much time apart are beginning to quietly resign."

Those who left town in August have not spoken to their families since, she said.

"There is practically no communication with them. Relatives are hoping that everything is okay with them."

- 'Went after money' -

Many men have been enticed by the opportunity to earn double what they usually make, she said, adding that their monthly earnings at sea begin from around 50,000 rubles ($790).

Russia's intervention in the distant conflict has divided local military personnel.

"Some want to go to Syria but are rejected because of their age and health and others collect papers to avoid going due to health," she said.

In the end, supply exceeded demand.

"This has more to do with money than patriotism," she said.

"Because the war is far it is hard to imagine that we are protecting our homeland. Although there are those who believe that the enemy should be strangled in his lair."

"Those of my acquaintances whose children went there -- they went after money," she said.

"They have been promised good salaries. Some are even hoping to buy apartments when these events are over."

Last month the authorities said a 19-year-old soldier serving at Russia's Hmeimim base in Syria hanged himself, in what became the country's first confirmed casualty of the intervention.

The defence ministry chalked up the suicide to relationship trouble but his family contested the claim, pointing to a broken nose, jaw and other injuries.