Russia is preparing to put 24 Ukrainian sailors on trial after attacking and seizing their three Navy vessels near the Kerch Strait on 25 November. The vessels were heading to the Ukrainian port of Mariupol in a bid to strengthen the Ukrainian military presence in the Azov Sea, in response to Russia's ongoing blockade in the area. The Ukrainian National Defense and Security Council recognized the Russian attack as an act of unprovoked aggression and Ukraine has imposed a state of martial law in nearly half of the country in response. Meanwhile, Russian President Vladimir Putin has called the whole incident a Ukrainian "provocation" and the FSB is claiming Ukraine trespassed on Russia's territorial waters. We dug into the intricacies of maritime law to see whether Russia's accusations have any ground. Note: this article has been updated to include the last section "In whose waters?" and to include the Russian law "On the internal seas, territorial waters, and contiguous zone of the Russian Federation," and details on the absense of a duly published suspension. The map has been updated to reflect the fact that the Azov sea is considered to be the territorial waters of both Ukraine and Russia, according to a 2003 agreement, and the fact that the official border between Ukraine and Russia has never been demarcated.
The accusations
According to the Ukrainian Navy, on 25 November, the tugboat Yany Kapu and two artillery armored boats Berdiansk and Nikopol, were headed from Odesa to Mariupol. They notified the coastal post of the Russian border guards service and the seaports of Kerch and Kavkaz of the intended passage via the Kerch Strait, but were not answered. Then, the Russian border guard ship Don rammed into Yany Kapu and damaged its engine and hull. As the Ukrainian ships approached the Kerch Bridge, Russia blocked the passage with a cargo vessel, however moving it aside to let its own ships pass. Additionally, Russia deployed several more seacrafts, as well as K-52 combat helicopters, and even Su-25 fighter jets in the Kerch Bridge area. After the blockage, Ukrainian ships headed back to Odesa, but shortly after they crossed the 12-nautical-mile baseline and reached neutral waters, the Russian ships opened fire on Ukrainian seacrafts wounding at least one sailor, reported the Ukrainian Navy as of 20:33. Yany Kapu and Berdiansk lost engines and were seized by Russian special forces. The third seacraft, Nikopol, was surrounded by Russian ships and forced to follow their course.Read more: Russian attack on Ukrainian ships near Kerch Strait – full chronology
According to Russia, the group of three Ukrainian military ships (two cutters and a tugboat) heading the newly established naval base in Berdiansk did not ask permission to enter the Kerch Straitю A document published by the FSB claims that the Marine administration of the Kerch port had to be informed 48 and 24 hours prior to passage and receive confirmation 4 hours prior to passage, claiming that the Ukrainian ships had not done that. It says nothing of the Russian border service ship Don ramming through the Ukrainian tugboat Yany Kapu, despite a video of the episode being published by Russian sailors. It also makes no mention of the lethal fire of the Russians, speaking only of warning fire and three wounded. Russia claims that these measures were needed because “the artillery installations were uncovered, raised at 45 degrees, and directed towards the ships and boats of the Russian Federation.” However, the photographs published by the FSB don’t show the two artillery cutters, depicting only the tugboat which usually doesn’t carry artillery. Belarusian journalist Franak Viačorka noted in twitter that the artillery marks on the ship Berdiansk show that Russians were aiming at the crew and not the engines.Thus, Russia is claiming that:
- the Ukrainian ships needed to inform the Kerch Marine administration 48 and 24 hours prior to and get permission 4 hours prior to passage through the Kerch Strait;
- Russia had a right to close the Kerch Strait for the Ukrainian ships and the Ukrainian ships violated P.3 Art.25 of the 1982 UN Convention on Maritime Law and P.2 Art.12 of the 1998 Russian law #155-FZ "On the internal sea waters, territorial waters and the adjacent zone of the Russian Federation" when they entered Russia's territorial waters at 44°52'N 36°31'E at 7:10;
- the Ukrainian ships violated the 1982 UN Convention on Maritime Law and the 1998 Russian law #155-FZ "On the internal sea waters, territorial waters and the adjacent zone of the Russian Federation" when they didn't obey the Russian border guards' orders to stop, which is why the Russian ships shot at the Ukrainian ships according to pp24,25 of the Russian state decree #80 “On Approval of the Rules for the Use of Weapons and Military Equipment while Protecting the State Border of the Russian Federation and the Exclusive Economic Zone and the continental shelf of the Russian Federation" (2010).

Territorial waters
The territorial waters of a state, or the 12-mile (22.224 km) strip of water adjacent to its coast, are considered sovereign territory of the state. However, foreign ships (military and civilian) are allowed innocent passage through them, according to Art.17 of the 1982 United Nations Convention on the Law of the Sea. P.1 Art.36 of the same Convention outlines that "in straits referred to in article 37 [used for international navigation], all ships and aircraft enjoy the right of transit passage, which shall not be impeded." A border at sea is not the same as a border at land. Vessels from different countries are allowed to travel through the territorial waters of another state.Thus, Ukraine couldn't have violated the territorial borders of Russia in the first place by passing through them. That's not how maritime law works.
Therefore, not only did Ukraine not violate the territorial waters of Russia, it, in fact, had entered its own territorial waters, according to an international agreement Russia is a signatory to. Moreover, speaking in terms of international law, the territorial waters around Crimea belong to Ukraine in the first place.
2003 Ukraine-Russia Treaty: freedom of navigation
The Ukraine-Russia Treaty on collaboration in using the Azov Sea and Kerch Strait signed by Russia and Ukraine in 2003 is the base document regulating the two countries' usage of the Azov Sea.According to it, the Azov Sea is historically the internal sea of Ukraine and Russia. Accordingly, all trade and military ships, as well as other state ships under Ukrainian or Russian flags used in non-commercial goals, have the freedom of navigation in the Azov Sea and Kerch Strait.
Thus, Ukraine should have been allowed innocent passage through any Russian territorial waters according to the UN Convention, not even mentioning the Kerch Strait, which has a separate law governing Russia's and Ukraine's actions.
Russia still recognizes the Treaty as valid. Therefore, Russia's complaints about Ukraine "violating its territorial waters" are completely bogus.
Can Russia close down the Kerch Strait?
Russia claims it had a right to close the Kerch Strait for the Ukrainian ships and the Ukrainian ships violated P.3 Art.25 of the 1982 UN Convention on Maritime Law and P.2 Art.12 of the 1998 Russian law #155-FZ "On the internal sea waters, territorial waters and the adjacent zone of the Russian Federation" when they entered Russia's territorial waters at 44°52'N 36°31'E at 7:10, according to the FSB material. First of all, that location (triangle 2 on the map above) is located outside of the territorial waters of both Russia and occupied Crimea. Second, the mentioned legal acts state that "the coastal State may, without discrimination in form or in fact among foreign ships, suspend temporarily in specified areas of its territorial sea the innocent passage of foreign ships if such suspension is essential for the protection of its security, including weapons exercises. Such suspension shall take effect only after having been duly published." According to Art.2 of law #155, the suspensions are published in the "Notices to Mariners," which, in their turn, are published on the siteTrending Now

Russia did not have any right to arbitrarily stop the Ukrainian ships.
Can Russia fire on Ukrainian ships?
The FSB cited pp.24,25 of the Russian state decree #80 “On Approval of the Rules for the Use of Weapons and Military Equipment while Protecting the State Border of the Russian Federation and the Exclusive Economic Zone and the continental shelf of the Russian Federation" (2010) as the legal grounds on which Russia shot at the Ukrainian ships. The decree #80 states that weapons can be used against vessels violating rules of crossing the Russian state border and rules of conduct established by Russian law and international agreements. However, pp.24,25 also state that the decision to use weapons is made either by the head of the border service or by the border ships themselves, "when delay in the use of weapons creates an immediate danger to their life and health, the life and health of other citizens, the danger of damage or destruction to border ships (aircraft), other ships, aircraft and may entail other serious consequences (traffic accidents, disasters, sabotage, and other public disasters)."The Ukrainian ships were not posing any immediate danger to anybody. They were leaving to Odesa. Which means that the border guard ships had either violated the decree #80 cited by the FSB, or had orders to fire from the HQ.
"If any warship does not comply with the laws and regulations of the coastal State concerning passage through the territorial sea and disregards any request for compliance therewith which is made to it, the coastal State may require it to leave the territorial sea immediately."Also notably, when firing on Ukrainian warships, Russia contradicted its own 1998 law "On the internal seas, territorial waters, and contiguous zone of the Russian Federation," article 19 of which states:
- that Russian authorities may require a foreign warship to immediately leave if it doesn't comply with Russian laws;
- that during peacetime, all disputes between Russian authorities and a foreign warship should be resolved by diplomatic means;
- that attacks on warships can be carried out only if the warship attacks first.
Ukraine had not attacked first. This means that Russia had violated another one of its laws.
In whose waters?
There has been plenty of speculation regarding in whose waters the attack on Ukraine's ships took place, and great relevance placed on the fact that Russia's Izumrud used lethal force against Ukraine's Berdiansk several hundred meters outside the territorial waters of occupied Crimea. On the map, the coordinate where Russia allegedly fired the salvo against Berdiansk is marked with 6; the spot where the Ukrainian ship sent its distress signal is marked with B. Given that these two spots are very close to each other, it's highly probable that the attack indeed took place here, a few hundred meters outside of Crimea's territorial waters. However, the location of the shot has little relevance from the viewpoint of maritime law. If we don't recognize the occupation of Crimea, the Russian border ships are present in the territorial waters of Crimea illegally, and a shot fired at a Ukrainian ship is also illegal. If we consider that Russia has a right to be there, de-fact recognizing its "annexation" of the territorial sea together with Crimea, then it is irrelevant where the shot took place. According to the UN Convention on Maritime Law, outside of the 12-mile zone lies the exclusive economic zone of a state (up to 200 miles from the coast), in which a state has the right to use the sea economically and an obligation to preserve its resources; and the contiguous zone (24 miles from the coast), in which a state has the right to punish the infringement of its laws committed in the territorial waters.Thus, if we decide that Russia had a right to pursue and shoot at the Ukrainian ships traveling to the Kerch Strait, it is irrelevant where the shots took place, inside or outside the territorial waters.
Read also:
- Russian attack on Ukrainian ships near Kerch Strait – full chronology
- Russia takes 24 prisoners of war after attacking Ukrainian ships in Azov, televises “confessions”
- Martial law to be imposed in nearly half of Ukraine. Here is what will change
- Russia attacks Ukrainian ships near Kerch strait - video, audio intercepts