Although my shipmate overreacted, his caution was well-founded: entering an unfamiliar harbor at night should be avoided unless there are no better options. Harbors are usually next to cities, and Paris is not the only “City of Lights”. The lights on the nav-aids will be lost in a clutter of streetlights, traffic lights and neon signs. It’s very easy to mistake a flashing red traffic light for a nav-aid. Also, the combined glow of all the lights makes obstacles nearly invisible. Once I almost hit an anchored ship, it’s presence only perceived at the last minute by the absence of lights.

The other facility you lose at night is your sense of perspective: all the lights appear on the same plane, and it’s almost impossible to divine which lights are closer and which are farther away. Often you don’t realize which is the closest light until it is beside you, and by then can be too late: “Hey, is that the light that marks Danger Shoals?” Crunch.

To the rescue comes the magic box of the GPS. The GPS is an amazing instrument: it can tell you where you are in the world with accuracy previously unheard of. Unfortunately, this same accuracy was unheard of when the nautical charts were surveyed. In other words: that rock isn’t necessarily where the chart says it is. It’s probably really close, but it might not be exact. If you look carefully at the charts, you’ll often find a notation like this: “Portions surveyed by USS Ranger, 1890”. It seems incredible, but it’s true: that up-to-the-minute chart-plotter contains data collected before television, the band-aid, and neon lights were invented. So, counting on your GPS to guide you when there are no other references is a recipe for a Bad Day. In fact, the US Coast Guard has a specific category of accident entitled “GPS Aided Groundings.”

Without getting too deeply into navigation (a complex subject, covered elsewhere), the best way to avoid approaching a harbor at night is with good planning. Remember the equation from your navigation course: “Time = Distance / Speed”? You can use that to plan your arrival. If your destination is 60 miles down the coast, and your boat cruises at 5 knots, you are looking at a 12-hour trip. If you depart at 8am, you will arrive at 8pm – not good. A better plan would be to depart at dusk, call it 6pm, so you can arrive at dawn, 6am. Remember to plan for other factors and contingencies, too: contrary winds or currents might slow you down, or certain tides might make a harbor dangerous to enter.

Even with good planning, you will sometimes find yourself approaching a harbor at night. In this case you have options you have two options: slow down or heave-to. Slowing down sounds simple, but it’s amazing how difficult it can be to throttle back when you are off-shore. All of your instincts tell you to complete the voyage, get into harbor where it’s “safe”. But remind yourself that reducing velocity can increase your safety: “Sea-room” is not just for the fighting ships of old, it means safety for all vessels at sea.

“Heaving-to” means to stop your boat’s motion through the water in the most comfortable (and safe) way possible. Remember: harbors are busy places. If you are going to heave-to, it’s best to do so before you become a hazard to ships and boats going about their business in the harbor. Five miles off is a good rule of thumb, but each harbor is different, use your judgment.

There are rare situations where you need to enter a harbor at night: if you have a crew member who needs medical attention, or if severe weather is rapidly approaching. In such a case, it is a good idea to get help. A call to the local Coast Guard will usually elicit an immediate and helpful response: they’d much rather keep you away from the rocks than try to pull you off them. Do not be shy with the Coast Guard: they really are there to help. Another useful aid: a friend on-shore with a cell phone. Even if your friend has no boating knowledge, he can tell you if you are getting close, moving away, or going sideways. You can use a strong flashlight to identify yourself to your shore-guide; if that doesn’t work, use a flash from a camera. Remember to warn your crew -- and to close your own eyes -- before you flash; you don’t want to be blind for the next several minutes. Again, these are options of last-resort: if it is possible to safely stand off-shore until daylight, it is best to do so.

It’s very tempting, when approaching your destination after a long trip, to rush to enter the harbor under less-than-ideal conditions. You and your crew are usually tired, wet, hungry and late, and a good night’s rest is only a couple miles away. But waiting a little bit Is almost always the prudent tactic.” A bonus: sunrise at sea can be one of the most spectacular natural events you’ll ever witness.