Could you be sailing too fast in some conditions? After all, it’s rare that a mono hull (single hull) cruising sailboat’s speed can come close to that of her powerboat cousin. Look to the Navigation Rule six to find the answer. Regulate your speed based on these five vital factors:

1. Visibility Conditions at Your Location

Fog comes to mind right away. But so do rain showers, squalls, heavy weather with blowing spray, dust storms, or even nighttime. Nighttime? Our perception decreases after sunset, as does our ability to see unlighted or dimly lighted objects. Studies show that we are often most sluggish in the wee hours of the new day (around 0200 or 0300 in the morning).

So, it makes good ‘sea sense’ to reef at night and carry a smaller headsail. Big Genoas can block visibility and turn into a handful if a squall comes up. Keep speed down at nighttime for easier sail handling and less stress all around for skipper and crew.

In confined waters if visibility drops, consider anchoring. This could be the most seamanlike action–in particular with a small crew.

Realize that if you are underway, you are obligated to sound the proper signals for a vessel under sail alone–one prolonged and two short blasts every two minutes. If you are under power (or sail and power, which makes you a power-driven vessel) the signal will change to one prolonged blast every two minutes. (also see Rule 35 for sound signals for a vessel at anchor).

Right off the bat, you lose one crew to full-time duty to sound the proper fog signal. Add to that the intense demands of a lookout in low visibility (by all means available–sight, hearing and installed electronics–not just AIS or radar!) and you get the picture.

Consider the alternative. Choose a spot out of the way and lower the anchor. This can melt away stress faster than most any other action you take. You’ll still need a lookout, but the additional burden of navigation will be over. Make the call based on your local knowledge and experience in the area. A bit of time delay getting home will be a lot better than a grounding or collision.

2. Traffic Density Where You Are Sailing

Does your sailing route take you close to or near an area frequented by commercial fishing vessels or anchored small boats? Will you sail near traffic lanes or traffic zones? Sail clear to avoid the risk of collision.

Navigation Rule nine cautions sailing vessels or vessels less than 20 meters (65.6 feet) not to block or hamper boats or ships in narrow channels or waterways. Just another good reason to ‘stay clear to stay safe’.

3. Your Vessel’s Ability to Maneuver, Stop or Turn

You may have heard the old recommendation to never proceed faster than the speed in which you can bring your vessel to a complete stop in a distance equal to one-half the present visibility. That might seem silly for small boats, and indeed, it applies more to big ships, but it does make good ‘sea sense’.

If in a blinding squall, lower your speed to the minimum or stop the boat. The wisest move may be to heave to and wait it out. Fast moving squalls rarely last longer than a half hour or so. And, if you stop or slow your boat, the weather system will pass by faster than if you tried to run before it.

In the Coast Guard, we sometimes encountered vicious squalls in the Caribbean Sea that lowered visibility to the point to where our bow was invisible. The radar could become so cluttered with rain and sea return, that our ability to pick up a vessel by radar would be next to impossible. We would back off the throttles to give us just enough speed to maintain steerage.

Matter of fact, the single factor of safe speed played a crucial role time and again in saving lives when I was in the US Coast Guard. Read this true sea tale from long ago…

Slow Speed Saves Lives in Operation ‘Able Vigil’

In the early 90’s Cuba’s Fidel Castro opened a narrow ‘window of opportunity’ to allow citizens to take to the sea in tiny rafts or boats to head to the US. Many of these craft were not seaworthy with just a few inches of freeboard. They were overcrowded and often in danger of capsizing. Many had no lights and were too small and low to the water to pick up by radar.

Our mission was to rescue them as soon as they entered International waters. At nighttime, the difficulty of rescue increased exponentially. We slowed our speed to a crawl and stationed lookouts forward and aft. And they looked and listened. We often never saw them–but heard them!

If you recall, listening is mandated by Rule 5 in the Navigation Rules. And it worked. We would pick up voices of the people in their tiny rafts before they were sighted at all. The result? This combined Coast Guard/Navy effort rescued over 30,000 people in one of the most successful peacetime sea rescue operations in US maritime history.

4. Nighttime Background Lights

Imagine a chameleon that rests atop a huge green leaf. That reptile will turn green like the leaf to become next to invisible. The same can happen at nighttime when you sail in areas with lots of city lights. New York city can be a magical place to sail through at night, but small boat navigation lights will be next to impossible to spot if superimposed with the bright lights of the shoreline.

Consider what the other guy or gal sees from their boat. Pretend that you can beam aboard their boat and look back at your boat. Will you–like the chameleon–be invisible in the background scatter of lights? Slow down if necessary and increase visual scans (by eye and binocular) when lots of lights are present at night.

5. Your Draft Relative to Water Depth

Power vessels that travel at high speed in shallow water can experience ‘stern squat’. In water depths of about 2X or less than your boat’s draft, the stern of your boat will drop (squat) toward the bottom. This makes the rudder and propeller inefficient and steering sluggish. And in extreme conditions, your rudder or propeller could contact the bottom with catastrophic results!

Small sailboats may experience similar conditions in shallow channels. For example, with a 3-foot draft, you should slow down in water depths of 6 feet or less to maintain positive rudder and propeller performance. Check your chart, correct for tide and transit the channel at the slowest speed practicable.

By Captain John Jamieson @