Nothing to do with the logo.

Daniel, is that a photo of part of that Christo installation in Central Park?

It sure is Nick, I took this photo at 7th ave at 108th Street going up the stairs to the Great Hill. Sorry to say by the end of the week it will all be gone. These gates are already gone.

Back to the Mariners font. Yes, it's custom, as Dan said, but if you want to imitate it (non-commercially, of course), look for Latin Serif fonts, like Spike Incised.

Latin looks a lot like the older logo seen here. If you add a stroke to it, it would really resemble the new logo in your sample.

Dan - is that one of your pinhole pix? Either way it's a nice one. I'll miss those gates too. Sounds like you covered more of the park than I did.