I got there as fast as I could. With reports flying out of central Brooklyn that a live seal had been spotted in the Gowanus Canal -- as likely a place to host aquatic habitation as Mars or even Loch Ness -- I zipped over to the canal zone to get my own look. See, I've written about the canal's problems periodically over the years, referring to it as a "corpse of water," "an open sewer," "the River Styx of Brooklyn" and "a really, really bad place to take a first date." But I also covered the opening of the so-called "flushing tunnel" in 1999 that brought "fresh" "water" into the canal. Later, I raced over after hearing subsequent reports of crabs -- live crabs -- munching on fish -- live fish -- in the much-clearer water. Buddy Scotto, a neighborhood activist who has devoted decades to cleaning the canal, promised then and there that we would someday celebrate the canal's rebirth with a swim. Who knew that a seal -- call him "Messie" in honor of the beast of that Scottish loch-- would beat us to it? Or did it? "I don't know about that seal," Scotto told me while we stood on the Carroll Street bridge, the only motion in the water caused by the methane that constantly bubbles to the surface. "I never saw it." City Councilman Ken Fisher shared Scotto's pessimism, but, likened the return of life in the canal to the return of professional baseball to the borough later this summer. "In Brooklyn," Fisher said, "apparently all things are possible." (He then made an unforgivable pun about how the marine mammal probably just wanted to put its "seal of approval" on the canal -- a pun so bad that I promised I would not publish it. Oops!). But nearby, Mark Karwowski -- the man who became an overnight celebrity when The Brooklyn Paper put his seal sighting on the front page -- was defending his eyesight. Yes, strange as this may sound, but no one in the "Show Me" borough seems to believe that Karwowski, a teacher at the High School of Telecommunications in Bay Ridge, actually saw a seal on that snowy day last month. Even though harbor seals are prevalent in New York waterways, most Brooklynites believe Karwowski saw a very big rat, a dead dog or, enthralled by a wintry tableau, a floating trash bag. But Karwowski is sticking to his story: On that fateful day, when heavy, late-winter flakes were falling on the historic Carroll Street bridge, he was so moved by the beauty of the canal (this guy's nuts, right?) that he paused to look. And, could it be, there, just 15 feet from the bridge, a seal looking right back at him? "That's why I say it was a haiku moment," Karwowski said. "We made eye contact. Then he disappeared. This was not a plastic bag. I know what I saw -- and I know everyone thinks I'm full of s--t." (No, not you, Mark. Just the canal -- although what New Yorker makes eye contact with ANY living being?) No matter what Karwowski saw, everyone seems willing to exploit the fish tale, especially people hoping to block commercial development in the area in favor of parks along the "reborn" waterway. That explains the Brooklyn Paper's front-page gushing (as well as claiming two other wholly unconfirmed and unattributed sightings): "The sightings," the paper opined, "[are] another reason to add to the growing list of why retail development along the canal should be carefully controlled." To put the matter to rest, the Gowanus Canal Community Development Corporation is offering $100 to whomever snaps the first photos of Messie. But take note: The photo has to be better than those grainy shots from Scotland. --30-- email: gershny@yahoo.com