glad you got that much -it'sRussia only Blue Water Access, except the Pacific, which Russia doesn't use much for naval ops, except to extract Arctic mineral wealth.
The problem is Poroshenko would not guarantee the lease -and this wasn't the first time!
Russia, Ukraine agree on naval-base-for-gas deal - 2010 ( before the Euromaidan)
https://www.cnn.com/2010/WORLD/europe/04/21/russia.ukraine/index.html
Ukraine and Russia had been at odds ever since the "Orange Revolution" swept Yanukovych's anti-Russian predecessor Viktor Yushchenko to power in 2005.
Throughout his time in office, Yushchenko repeatedly threatened to expel Russia's Black Sea Fleet from Sevastopol. The Russian military lease there was scheduled to expire in 2017.
with the Euromaidan tearing up this agreement, and the Kyiv faction firmly in power in Ukraine -Putin had no choice
It's really great you have people to look that up for you so you can cut'n'paste. As the linked picture proves, the Russians have a few "blue water" ports including Severomorsk, home of the North Fleet. The problem is that it needs icebreakers for part of the year....but global warming is helping with that. (Putin says "yay!")
Sevastopol doesn't freeze over, plus there's the monetary investment of dry docks, repair facilities, fuel dumps, ammo dumps, etc. Putin could have cut a deal because, because they are Russians and Ukrainians, everyone has their price. Instead Putin prefered to save money and spend lives.