Andrew Hopkins reports for TRT World on Bosphorus Naval Watch - a group which came under the limelight after releasing pictures of Russian soldiers apparently bearing weapons while passing through the Turkish strait
A photograph - shown below - of a man on board a Russian ship holding what looked like missile launcher pushed the Bosphorus Naval Watch group onto the international stage.
But this was not their only picture to make news. Another photo was taken of the same warship - Caesar Kunikov - but on a different date.
This time it showed three men lying down on deck in what looked like sniper positions. Some news outlets said they were actually sunbathing.
But whatever the truth may be, Bosphorus Naval Watch member Yoruk Isik has some theories about what's been happening on this Russian vessel.
He believes one explanation is that it could be just part of Russia's foreign policy to grab the world's attention.
This would also help to explain another incident recently where a Russian jet flew close to a US warship in the Baltic Sea.
As mentioned in my report in the video above, Yoruk thinks these measures would be an overreaction from Russia if it is worried about security.
That's because the Turkish coastguard and police ensure safe passage through the Bosphorus.
But Yoruk thinks incidents like those above could also be linked to something more personal.
"I even thought that it was maybe because many Russian soldiers use the Bosphorus as a photo opportunity for their Facebook pages.
"Later on, on the very southern exit of the Bosphorus, he [the soldier carrying the rocket launcher in the picture] put it on his shoulder and that is the most scenic part of Istanbul.
"Maybe it was a personal event, because when we looked at the sequence of pictures afterwards, when he passed under the first bridge in Istanbul, he was not carrying it."
Watching ships on the Bosphorus also gave the group an indication of what was likely to happen before Russia started airstrikes in Syria last September.
Alper Boler said, "We were already seeing very heavy traffic, mostly with landing ships shuttling between Russia and Syria.
"Almost every day you could see almost a couple of ships going and coming back empty. It went up even further up because we started seeing some civilian ships joining in with military gear on them."
He added, "On the day that they actually announced that they were involved in the conflict, it became obvious what had been going on."