Ukraine has no navy and has sunk more warships against a blue water navy since Falklands however it's not like Russian navy is traveling thousands of miles.
FYI: the distinction of brown, green and blue water navy has to do with
range,
autonomy and
seakeeping of ships
not their combat capabilities.
Royal Navy in 1982 was a typical blue water navy but it would be destroyed by Soviet green water fleet (i.e. subs, missile boats etc and without the large vessels) even without air support.
Seakeeping is also more important than range and autonomy. Karakurt built at Zaliv Shipyard in Kerch can go around Europe to Baltiysk but it will be never able to go outside of waters where the sea state can exceed what the hull is capable of handling.
Problem for Russian navy and the whole Russian military, amongst many problems, is they don't fight in a combined arms way there's no Joint-Command in their military. This is what happens when you don't have air superiority and good IRS capabilities.
The Black Sea Fleet has been at war for
two years against an enemy armed with anti-ship missiles and anti-ship drones and supported by persistent ISR.
When USN fought in Vietnam the opponent had neither as well as no submarines or sufficient air force to threaten the USN task forces including Carrier Strike Groups. For example the Gulf of Tonkin incident in 1964 involved Vietnamese
torpedo boats. Later North Vietnam received four small missile boats (60t) of Komar class armed with two P-15s each, and later Osa II missile boats. The range of those missiles was 40km but NV had no ISR support so it would have to close within striking distance of USN task forces which would be very difficult.
USN is "invincible" not because it has invincible ships or because it can perform joint operations but because it has the ability to attack targets while keeping its task force outside of enemy strike range.
Ukraine can harrass the BSF consistently because it can use drones which can stay at sea for longer periods of time, are not easily detected and are guided with the help of persistent satellite coverage. The drones are also relatively cheap to produce so it can send them repeatedly and wait until an attack succeeds. You only see the clips of when the attacks succeed, but they happen regularly and are just as regularly repelled which tends to put human operators in state of false security.
Also note which types of ship Ukraine is attacking - they are not ships designed or equipped to handle this type of warfare. Western navies equip its recent designs with RCWS because of threats posed by small boats in Persian Gulf or near Horn of Africa. Russia never considered such threats because it has a green water navy protecting its coastal waters and Russian ship designs reflect that.
To my knowledge there is no ship in the Black Sea Fleet that is equipped with an electro-optical sensor head and RCWS designed for such tasks.
Project 22160 patrol ships in particular were designed as low-cost vessels for basic patrol duties in low threat environment. They have only the main gun and two manned 14,5mm machine gun stations on each side of the bridge. They were ordered for political and economic reasons. Navy didn't want them.
Russia has designed its ships to meet requirements of its general naval strategy, which included deterrence against NATO, not Ukraine. In this strategy Russian ships such as Steregushchiy or Buyan-M or Karakurt served as forward sensors - radars and sonars - for shore-based missile systems and aircraft. They were deployed at sea but they were the first line of defense for land assets. Russia planned to project power
from land to sea, not the other way around.
Those are the confirmed losses, except for the latest Ropucha and Bykov.
So I view it differently: it's been two years, and BSF is still in capable of combat operations because it only lost a completely useless, poorly maintained cruiser that barely had any working systems - see leaks of maintenance reports after the sinking. Their problem is lack of an opponent at sea. Drones are not enemy ships but enemy
munitions.
Considering the structural and institutional weakness of the Russian navy Ukraine is
worst performing at sea. They do much better on land or against the air force which are relatively much stronger.
Don't know why they keep them there...they are destroyed like sitting ducks while doing practically nothing for the war effort.
If Russia removes the ships then it loses physical control of the sea. Whoever has the sea maintains control of escalation.
Dark blue is
contiguous zone. Light blue is EEZ.
A foreign navy can sit outside of contiguous zone without consequence as long as it doesn't violate UNCLOS - see SCS disputes.
NATO ships sit at port because it doesn't want risk an incident with Russia while WMF is at sea in force. However if WMF is not at sea then NATO takes over and it will in turn be Russia who will want to avoid an incident since NATO has full right to be there.
Even if we exclude Turkey (which would absolutely take part if only to assert itself independent of US/EU) it still leaves Romania and Bulgaria which have up to 6 frigates, 5 corvettes and 7 missile boats that it can deploy. If Russia decides to challenge NATO presence it will be attacked by Ukrainian drones. All of the frigates also have sonar which will be a problem for the submarines. So Russia must stay "at sea" even as it tries to keep its ships at port as much as it can.
Also if WMF withdrew a concentrated attack by drones against the Kerch bridge or the ports or saboteurs penetrating from the sea would be a question of time. Russian patrols even if sporadic make planning of attacks difficult. Ships provide constant presence while maritime patrol aircraft can only stay in the air for a limited number of hours. Even maritime UAVs - which Russia doesn't have - would have limited endurance and sensor range. The ship is always there but it also means it is always the target.
It's free PR stunt and humiliation for Russian navy.
NATO ships 50km from Crimea will be far worse because by laws of the sea once they're there you can only
force them out.
Also NATO aircraft flying over Russian ships in international airspace is considered provocative but NATO aircraft flying over NATO ships in international airspace is not so NATO will put ships at sea as justification for moving its aerial assets closer. But to do that they first must be able to plausibly move in their ships without creating an incident which is only possible if Russian navy is out of theater.
I wonder if these attacks would've been prevented if Russia maintained control of Snake Island.
Ukrainian drones move along different routes.
Snake Island was captured to disrupt maritime transit to Odessa which looks like this:
