Thanks for comments fellows. I agree it might not be the most cost-effective solution, but: I think you're looking too close to ship itself. I mean, there is an AW-609 involved which has range of 2000 km with speed of 500 km/h. Roughly it could mean a 500 km circle (ok, not a circle but distance, at least) of patrolling area from the ship + censors of AW-609... Am I right?
I also agree it would be rare to end up situations of extensive rescue missions but if you'll do, wouldn't you want ship that could send several helicopters, fuel them at sea, change crews and take in all survivors easily? I also have to explain that this not going to be situated in the Baltics but in Barents Sea. Perhaps this map tells you more... Also this kind of ship could be useful in wartime in ASW or minelaying missions or other as JSB noted.
Oh, and the ship itself; the glory goes to Shiplover and especially to Superboy