The Russians had three lines of action in those waters.

First, to capture Sulina, and to destroy the squadron lying at anchor in its roadstead; second, to capture Batoum and its much-envied harbour; third, the somewhat undignified action of sending out fast vessels, mostly mail-boats, armed with a couple of guns, their object being to destroy the Turkish coasting trade.

These vessels were most difficult to catch, as they always watched their opportunity to slip out of their strongholds when the Turkish ships were employed carrying troops, or otherwise engaged.
There was, I venture to think, some illegality in this conduct of the Russian mail-boats.
These vessels were not regular men-of-war, and they did not take their prizes into port for adjudication, as is usual in war, always burning what they could catch and capture.

However, during war I suppose all must be considered as fair play.

While on the subject, I will recount one or two exploits performed by these enterprising mail-boats.