Gliding along, hour after hour, seemingly to nowhere … water, water everywhere, and little of it choppy … would not be such a bad way to spend a day, if it weren’t for the other 2,100 people on board a cruise ship.

A sail day, in cruising parlance, is one in which you do not touch land from sunrise to sunset.

Most passengers emerge from their rooms to prowl the (10) decks accessible to guests. And eat. And then they sit in the heated spa area. Followed by lunch. And then some of them go off to various classes and self-improvement sessions and thinly veiled attempts, by the Celebrity line staff, to sell you something. And have a snack.

Some of the activities available as the Constellation hurried around the tip of Denmark and took aim at Germany:

9 a.m — Ping Pong Open play, until 10

10.15 a.m. — Tai-chi class with your host Sarah (weather permitting)

11 a.m. — Understanding modern art seminar

Noon — Destination talk, Helsinki, Stockholm and Copenhagen

1.45 p.m. — Therapeutic reflexology demonstration

2 p.m. — Ballroom dance class: The cha-cha with the stars of the Constellation

The weather didn’t permit much of anything outside. The wind was blowing hard, and it never got above 55.

The sun made an appearance, though it was weak and low in the sky, as it tends to be in these northern climes, but it was enough to bring a smattering of cruisers into the open air of the 10th deck and onto couches, from where they took a bit of radiation while reading. Or eating. Or thinking about eating.

I have often heard that a ship’s company is a particularly superstitious lot, which led me to wonder how, in the name of Neptune, the Celebrity line allowed a nervous little woman from Saskatchewan to talk at great length about … the Titanic.

If you are flying, you can be sure none of the movie selections will include a plane crash.

Yet here was this person, set up in front of the enormous theater, rambling on about the “unsinkable” Titanic, and its encounter with an iceberg.

(The night before, the cruise director, a smarmy Briton who perhaps aspires to be a game-show host and answers to the initials “JC”, had mentioned the upcoming Titanic chat, noting that the Titanic struck the berg in the north Atlantic, while we were entering the Baltic “where there aren’t any icebergs — at least that I’ve heard about.”)

I missed the original Titanic chat here, but it was replayed on the internal TV system (which also includes day-old programming from CNN and the BBC, as well as Fox and MSNBC,  if you can’t bear to do without partisan blather for 12 days).

I saw the replay, and learned two things:

–The Titanic was mostly about Canada. Incredible, really. Nova Scotia, Halifax, Regina, Manitoba … all had major parts — in a Canadian’s telling of things.

–The subtext? The Titanic was thought to be unsinkable, but the Constellation, in fact, is. Otherwise, why would we be talking about an infamous disaster that occurred when most of the people on board perished while sailing through cold water? Because it can’t happen here!

I can’t imagine the crew would have signed off on this. I hope they didn’t even know about it, because it would make them nervous.  Maybe no boat has come to grief on a piece of ice from the Gulf of Bothnia in recent times, but who is to say we could not? Especially when tempting fate like this?

We old salts don’t like that idea.