Cockpit Navigation

[HenryC]

Here's a new story I'm developing for publication.  I thought I'd let you guys preview it, and maybe suggest some of your own tips and tricks.

Thanks, Hank


Those of us who love seamanship (as opposed to those of us who see a boat as simply a platform from which to fish, dive, or ski), are already familiar with piloting and dead reckoning.  We've read  books, studied our charts, and practiced the craft.  We can plot courses and calculate speeds, lay out a DR track, triangulate bearings, use a compass, in short, do all the tasks required to navigate our vessels safely without electronic aid.  In familiar waters, these skills may get rusty, but we know our way around and just a glance at the chart and a quick look around the horizon is all we need to get oriented.  If we are far from home, we quickly recall the rudiments of navigation and do what we have to in order to find our way.  But there's a big difference between turning around to go back to your home marina on a calm summer afternoon and trying to find shelter from a storm by ducking into an unfamiliar harbor in the middle of the night.

If you've been on the water for any length of time, you know sometimes you just can't do this.  You may be on an open boat, or in the cockpit of a cabin boat but needed at the helm. In the open, when you're very busy, you simply don't have the time to shoot a round of bearings and carefully plot them below on your chart table.  Your boat may not have a hard, flat surface where you can lay out a chart, or manipulate dividers and parallels, or even draw a straight line.  And on deck, the wind and spray may even make unfolding a chart a hopeless task.  On larger boats with protected work spaces, you may be the only person on board with the necessary piloting skills, and you may be needed at the helm or tending sails.  Its hard to navigate without an assistant, and it is next to impossible to navigate and sail in rough weather by yourself, or at least without crew you can trust to take the helm for a moment.

The trick to cockpit navigation is prior planning and common sense.  Do all your piloting before you leave, in the comfort of your kitchen table or during a quiet moment at anchor.  Circle or otherwise note on your chart all the landmarks you're likely to be using,  courses to be steered, flashing light characteristics, anything that might be hard to see in dim light or when you're really busy.  Note danger and turn bearings as well. Write them on the chart.  That's why it's made out of paper, so you can figure and calculate and take notes on it.  Sure, paper charts are expensive, but they are also very convenient.  They are meant to be used, they aren't just a maritime database, they are a nautical computer as well.  And if you do your scribbling neatly and legibly that information will still be there if you ever sail those waters again. 

Fold your chart in such a way that the parts you are likely to need will be quickly accessible, and those you don't will be inside the folds.  Wrestling with a large chart in a windy cockpit is not only  frustrating, its hard on the chart, too.  And when not in use, place the chart in a transparent plastic container to protect it from the weather so you can leave it oudoors, folded to your area of interest.  If a small craft or compact edition of your chart is available, take advantage of it, but first compare it to the more detailed chart you may have of the region so you will know what may be missing on it.  If possible, try to fold your chart in such a way that the latitude scale is visible so you can quickly estimate distances (1 minute of latitude = 1 nautical mile).  If you can, try to fold it so a compass rose is always visible, so you can quickly estimate bearings.  You may not have time to fiddle with protractors or dividers or straight edges.  Sometimes charts are printed so the grid lines are not parallel with the edges of the paper.  I personally find these very disorienting.  If you do as well, give it some thought and try to reduce the confusion by folding it in such a way that the confusion is minimized.  If you're sailing into an unfamiliar area, familiarize yourself with the chart; not just the seascape geography on it, but the cartographic layout as well.

There are parts of the world where magnetic compass variation is quite extreme.  In any event, make sure you understand your variation, and practice a procedure to quickly correct from Magnetic to True and back.  If necessary, write reminders on your chart or next to your compass on how to correct.  Today, with GPS  and magnetic bearings and courses being both used, it is very easy to get confused, and if you correct "the wrong way", it can be disastrous.  Incidentally, a good hand held bearing compass is a must.  Experiment with various models and when you find the right one, buy it, no matter how much it costs.  It is not only essential for navigation, it is probably the only backup or check you'll have on board to your steering compass. A good bearing shooter is easy to use and accurate even under miserable weather and motion conditions, I use the model nicknamed "the hockey puck" by sailors, but use whatever works for you.

A high quality pair of binoculars is essential for piloting, but I often prefer a monocular (half a binocular) for combat conditions.  It is lighter, easier to use and shelter from the elements, and you don't have to fumble with focusing both glasses separately. (Your brain will simply use the clearest image anyway, and discard the other, so properly taking advantage of a good pair of binoculars can only be done under ideal conditions).  As with a binocular, the monocular should be 7x 50.  It is the optimum combination of light gathering power, magnification and steadiness for all-aroud marine use.  Make sure you make some arrangements where you can quickly stash your glass out of the weather, but easily accessible, when not in use.  In a situation where you are reliant on optical aid, perhaps under survival conditions, you should not have to worry about your expensive equipment getting wet or corroded by salt, and you won't have the time to be groping around in the dark for lens caps, cases, snaps and straps or other accessories.

Proper chart work depends on laying  and taping down securely a chart (preferably one without any wringles or folds) out on a table where your parallel rulers, dividers and other drafting tools will be able to accurately transfer distances, locations and directions off scales and compass roses.  Lighting is also essential, preferably night-vision red.  Clearly, this is too much to ask for on most small boats, and is utterly unachievable in an open cockpit.  The alternative is to do most of your navigating when not actually underway.  But with a little planning, the less-than-optimum conditions of an open boat can be mitigated.  For example, simply spreading your fingers, or using any handy straight edge, can be used to transfer rough distances to and from the nearest latitude scale.  A chart compass rose displayed on a properly folded chart will similarly allow you to make course or bearing estimates.  And by planning your approaches cleverly ahead of time, you can minimize the need for accuracy.  Imagine this internal monologue:

"When the island north tangent bearing hits about 50 degrees I'll come to  240 and sail for two hours (about six miles) and I should be able to see the 4 second flashing green more or less at a bearing of about 200.  At that time, I can come to a northerly course and miss Middle Ground Shoal."

By picking the right approach, it may not be necessary to determine any of those numerical figures to a high level of precision.  Think of it as eyeball piloting.  You already know how to do it, but by planning your voyage ahead of time, you can make it easier on yourself by picking courses with lots of margin for error, giving all hazards and obstructions a much wider berth than you would normally do under ideal navigational conditions.  And always have a Plan B worked out ahead of time.

Of course, the ideal situation is to have competent crew.  You should teach folks who often go out with you the rudiments of boat handling and helm work so you will be free for other duties. And it is even more satisfying to show someone how to pilot and dead reckon.  Crew who get to participate in the actual navigation of the craft will soon be asking you for more time on the water.  It is wonderful to watch the expression on the face of someone that has just sucessfully plotted their first fix, or seen that predicted aid to navigation materialize on the horizon right on schedule. 

[shamblin]

This brings to mind the opportunity of getting/keeping sharp by doing the detailed piloting and navigating you would not really have to do in waters one is familiar with.   Also the challenges of doing everything at night.