The Black Sea Fleet is the fleet of the Russian Navy in the Black Sea, the Sea of Azov and the Mediterranean Sea. The Black Sea Fleet, along with other Russian ground and air forces on the Crimean Peninsula, are subordinate to the Southern Military District of the Russian Armed Forces. The fleet traces its history to its founding by Prince Potemkin on 13 May 1783 as part of the Imperial Russian Navy. The Russian SFSR inherited the fleet in 1918; with the founding of the Soviet Union in 1922, it became part of the Soviet Navy. Following the collapse of the Soviet Union in 1991, the Black Sea Fleet was partitioned between the Russian Federation and Ukraine in 1997, with Russia receiving title to 82% of the vessels.
The Ukrainian Navy is the maritime forces of Ukraine and one of the eight service branches of the Armed Forces of Ukraine.
Hetman Sahaidachny (U130/F130) was a frigate of the Ukrainian Navy that was originally built at the Kerch Shipyard as a Project 11351 patrol ship of the Nerey / Krivak III / Menzhinskiy class. Homeported at Odesa since March 2014, she was the flagship of the Ukrainian Navy, and a part of the 30th Surface Ships Division. Her major armament was a single 100 mm gun. As the Russo-Ukrainian war escalated, Hetman Sahaidachny was scuttled by Ukraine on 4 March 2022, from fear of the ship being captured by advancing Russian forces.
The Ukrainian Marine Corps, also known simply as the Ukrainian Marines, is the maritime land force service branch of the Armed Forces of Ukraine since 2023, responsible for conducting expeditionary and amphibious operations. From its modern foundation in 1993 up to 2023 it constituted part of the Coastal Forces of the Ukrainian Navy. It is used as a component part of amphibious, airborne and amphibious-airborne operations, alone or in coordination with formations and units of the Ground Forces in order to capture parts of the seashore, islands, ports, fleet bases, coast airfields and other coast objects from the enemy. It can also be used to defend naval bases, vital shoreline areas, separate islands and coast objects, and security of hostile areas.
The Ukrainian patrol vessel Sloviansk (P190) was an Island-class patrol boat of the Naval Forces of the Armed Forces of Ukraine. Originally named USCGC Cushing when in service with the United States Coast Guard, the vessel was acquired by Ukraine in 2018 and arrived in Ukraine on 21 October 2019. Sloviansk was sunk in combat on 3 March 2022 by a Russian air-to-surface missile.
Vinnytsia (U206) was an anti-submarine corvette of the Ukrainian Navy. Prior to joining the Ukrainian Navy she was a former KGB Border Guard patrol ship named Dnepr. In March 2014, she was seized by Russian soldiers and de facto came under control of the Russian Black Sea Fleet. The ship was returned to the Ukrainian Navy from Crimea on 19 April 2014.
Yuri Olefirenko is a mid-size Project 773 landing ship of the Ukrainian Navy. From her original commissioning in 1971 until the 2014 Russian annexation of Crimea, she was based in the Southern Naval Base at Donuzlav. Since then Yuri Olefirenko was relocated to Ochakiv. She was subordinated to the 29th Surface Ships Division. She was reportedly captured by Russian forces during the 2022 Russian invasion of Ukraine before being spotted still in active service on 3 June 2022. In 2023, an unconfirmed Russian report claimed the vessel had been destroyed.
10th Naval Aviation Brigade is the sole Brigade of the Ukrainian Naval Aviation established in 2004 by the merger of 9th Mixed Marine Aircraft Squadron, 316th Separate Marine Aviation Squadron and the 555th Naval Helicopter Regiment. It operates a vast arsenal of fixed-wing, rotatory and unmanned aircraft. It was previously garrisoned at Novofedorivka but is currently based at Mykolaiv.
The Kerch Strait incident was an international incident that occurred on 25 November 2018 in the Kerch Strait, during which the Russian Federal Security Service (FSB) coast guard fired upon and captured three Ukrainian Navy vessels after they attempted to transit from the Black Sea into the Sea of Azov through the strait on their way to the port of Mariupol. It was the first time that Russian forces had openly engaged Ukrainian forces during the Russo-Ukrainian War.
The battle of Berdiansk was a major battle which units of the Russian Armed Forces and Russia's Black Sea Fleet fought against the Armed Forces of Ukraine and the Ukrainian Navy. It occurred in the early days of the invasion as part of Russia's Southern Ukraine campaign, beginning on 26 February and concluding a day later on 27 February.
73rd Naval Special Operations Center "Chieftain Antin Holovaty" or the Special Operations Center South is the naval component of the Ukrainian Special Operations Forces. It joined the Ukrainian Navy on 1992 and became a part of Special Operations Forces in 2016, becoming the sole naval component of SOF. It is headquartered at Ochakiv.
1st Naval Guard and Patrol Division formerly known as 1st Security and Support Division is a division of the Ukrainian Navy, established in 1997 it is concerned with the defense of Ukrainian coast and guarding of the installations of the Ukrainian Navy. It is garrisoned at the Western Naval Base and currently comprises several gunboats, a control ship and an anti-sabotage ship.
The 28th Naval Auxiliary Division is an Auxiliary division of the Ukrainian Navy, based at Western Naval Base. It was originally established in 2014 as the 28th Separate Search and Rescue Division and was formerly stationed at Sevastopol. It is mainly concerned with providing support to combatant ships of the Ukrainian Navy.
30th Surface Ships Division formerly known as 1st Naval Surface Ship Brigade is a NATO certified division of the Ukrainian Navy. It is a combat active unit and is amongst one of the most highly active units amongst the Ukrainian Navy. It's flagship Hetman Sahaidachny is also the flagship of Ukrainian Navy. It was established in 1993 and is currently based at the Western Naval Base.
28th Surface Ships Division formerly called as the 5th Naval Surface Ship Brigade is a division of the Ukrainian Navy based at Ochakiv. It was established in 1996 at the Southern Naval Base in Balaklava but was transferred following the Russian Invasion of Crimea.
31st Supply Ships Division is a logistical division of the Ukrainian Navy concerned with providing logistical and technical support to other divisions of the Ukrainian Navy. It is based at the Western Naval Base and was established in 2018 by the splitting of the 8th Security and Support Division.
Dnieper Fleet is a fleet of the Ukrainian Navy consisting of two divisions and is tasked with patrolling and protecting the Dnieper. It was established in 2022 during the Russian invasion of Ukraine amidst threats of a naval invasion from the north by Belorussian Dnieper fleet. It is in control of several small scale naval bases along the Dnieper.
Ukraine 
Ukrainian Navy