Today’s attack on Sevastopol harbor by Ukrainian maritime drones (uncrewed surface vessels armed with explosives) will make headlines. And rightly so. Yet there is an aspect which could easily be overlooked; this time none of Ukraine’s drone’s appeared to penetrate the harbor. The attack comes as Russia undertakes a massive effort to increase the harbor’s protection against these attacks.
The entrance to Sevastopol harbor is now protected by no less than 6 layers of physical barriers. This adds to the patrol boats, helicopter patrols, anti-diver dolphins and gun emplacements.
Local Governor, Mikhail Razvozhaev, announced on social media that the attack occurred at 3.30am. He stated that one maritime drone was destroyed and that a second exploded on its own. His wording appeared to confirm that the attackers did not penetrate the harbor.
Sevastopol is the main naval base for the Russian Navy in Crimea. Although there have been efforts to disperse key assets to other bases, such as Feodosia, major warships remain there. It therefore remains a key target for Ukraine, especially as any planned counter-offensive takes place.
Russia’s Increased Defenses of Sevastopol
The original floating booms across the harbor entrance were as much for containing oil spills as preventing some form of attack. Indeed, the threat of Ukrainian attacks with surface vessels must have appeared both old fashioned and highly unlikely to the Russians at the start of the Invasion. However the pre-existing floating boom was occasionally closed to prevent unauthorized boats entering.
However in October 2022 Ukraine pulled off an impressive maritime drone attack on Sevastopol. Several ships were hit although none sustained lasting damage. However it revealed the ineffectiveness of the old defenses. In November more heavy boom defenses were added, both at the harbor entrance and at various locations inside the port. The beefed-up defenses appeared more serious, the sort of thing many would have imagined at the beginning of the war.
Yet on March 22 2023 Ukrainian maritime drones struck again. Again they did not score a major hit, but they did once again penetrate the inner harbor. These latest defenses are likely in response to this. Two more layers of floating nets have been placed on the outer side of the harbor entrance. And a row of six large pontoon barges have been anchored just inside the entrance. These in effect extend the harbor wall, narrowing the entrance. It is likely that additional obstacles are strung between them.
Analysis of radar satellite imagery shows that the pontoon barges started to be positioned between April 3-9, and have grown since. They are now on both sides of the harbor entrance.
Russia Sees Crimea Under Threat
Independent defense analyst Benjamin Pittet told Naval News that the new defenses are part of a wider effort to fortify Crimea: “Russian ships have been patrolling more often near the Kerch Strait these past weeks. On the ground, they’ve been setting up a large amount of trenches around key locations. Air wise, they are becoming more aggressive regarding NATO intelligence missions.”
The attack comes as Ukrainian forces are reported to have advanced across the Dnipro River north of Crimea. Pittet believes that the increased defenses show that Russia is scared of any potential action against Crimea. As well as investing a lot of resources into trench building in the Zaporizhzhia and Kherson regions, there are even trenches across the southern tip of Crimea, near Feodesia.
He also notes that there are now multiple batteries of air defenses around Sevastopol. “They have been moving air defenses around for months now, they are not static, they keep moving. In the city, but also around Belbek airbase.”
Whether the latest Ukrainian maritime drone attack was intercepted because of the new defenses remains to be seen. It is possible that, knowing of these defenses, Ukraine deliberately targeted outside the harbor. Either way this attack should be seen in the wider context of an expected Ukrainian counter-offensive. What it shows is that Russia will have to continue to invest in protecting its bases on Crimea.