The US litoral ships are 3500 tons 115m length. Russian Black Sea frigates 4000 tons 125m (https://en.wikipedia.org/wiki/Admiral_Grigorovich-class_frig...) Black Sea is deep everywhere, ie. there is no "litoral" area where those frigates wouldn't be able to operate due to their size. And their roles there are currently mostly those of "litoral" ships, like the land attacks.