It's the Christmas season. Forty merry cheer-spreaders cluster outside the deck of a house, singing carols to the party-goers inside. The hosts pass out eggnog and cookies. The opera singer leads the group in "We Wish You a Merry Christmas," and then the group paddles away, to the next party. Paddles?

Only on Seattle's Lake Union does Santa travel by sea kayak.

It started a decade ago. "I was talking with a friend who had a houseboat and we thought it might be a fun idea to carol for their party," said Bill Stewart, co-owner of the Northwest Outdoor Center (NWOC). Every year since he has organized several outings, donating the proceeds to the Seattle Children's Home.

Lake Union is unique in that there are large numbers of floating houses moored to docks lining the lake. Through word-of-mouth, referrals, and an ad taken out in the Floating Homes Association newsletter, Stewart finds three or four houseboats having parties who would like to be serenaded on each outing, and comes up with a different itinerary for each night. In 1996, he organized outings on four different nights.

I joined a crowd of merry paddlers at the NWOC dock, on the west side of the lake at 6 pm. Almost everybody wore headlights, and many sported flashlights covered with colored cellophane. Kayaks pulled out one by one, until the dock was empty, and then they launched the mother ship: a large triple kayak strung with Christmas lights, carrying vocalist Norman Smith, concertina player Master Thomas Slye, and Santa himself.

Slye started playing Christmas melodies as the mother ship passed the splatter of boats, and like rats following the pied piper, we coalesced into a fleet behind it.

The first houseboat was familiar to moviegoers around the country--it was Tom Hanks' home in the movie "Sleepless in Seattle." Loretta Metcalf and Jim Healy, the owners, were hosting an office party. We rafted together and sang "Jingle Bells" and "White Christmas," and then they passed out eggnog. With our voices thus lubricated and warmed up, we belted out the carols and munched on cookies.

After finishing most of the songs on our sheets, the raft broke up and we dispersed, once again following the mother ship into the darkness, across the shipping lanes to the north side of the lake, and party number two, at a two-story houseboat. The hosts here passed out cookies and cider, and cheered our efforts to keep up with the opera singer.

Yachts sporting bright Christmas lights passed behind us, but between parties the lake seemed quiet, peaceful. Most of us had never paddled at night, and though the city lights provided plenty of light for us to see, something about being out in the dark felt cozy and comfortable. Perhaps it was the extra clothing--no, it was probably the eggnog.

We paddled under the spooky dark towers of the old gas works at the north end of the lake, and then cut across the shipping lanes again. The bright mother ship looked like some sort of spaceship on the black water. Santa rode through the night on a surface of onyx, drawn along by paddle. The rest of the fleet spread out across the lake, jabbering and shivering.

We poked in and out of the houseboat alleys, and reached the final houseboat's dock. The mother ship backed into the narrow alley, past six houseboats on each side, down a corridor wide enough for five or six boats. We crammed in, filling the corridor with our vessels close enough together you couldn't see the water.

We were all stuffed by this time, but our hosts kept passing out drinks and snacks as we sang. Neighbors opened their windows and stood on their decks, enjoying our presence. The back of our group couldn't hear the singers at the front, and soon the songs came in rounds, words echoing out of time from back to front, and we all laughed.

"Who needs a paddle?" said Santa as we left. "I've got reindeer. Forward, Ho, Ho, Ho!"

For more information, contact the Northwest Outdoor Center at (206) 281-9694. The event is extremely popular and often fills before October, so sign up early.