Ask any offshore cruiser or racer about fog, and they'll likely have a story. Fog can be challenging, especially when you’re racing. Here are some expert tips for racing in the fog with electronics.
Electronics are aids to your senses; they should be used as references but not as absolute truths. Remember that in all low-visibility situations, slower is safer. The US Coast Guard recommends operating your vessel at a safe speed of 3-5 knots when navigating in low visibility, a speed that allows you to react quickly and with the ability to stop at a moment's notice.
Onboard Radar System
Like all equipment, get familiar with your radar system before a situation gets dire. The best time to practice using radar is when you don't need it, such as on a calm day when there's more than a few miles of visibility. Look at your radar display, confirm the different blips with visuals, and switch the radar range up so you can find its shortcomings. Depending on your system, switch the radar among the maximum, middle, and short distances, and practice having vessels and other objects in range so that you can test the system. Familiarity will help when conditions turn south.
In low-visibility situations, dedicate one crew to radar display watch. They should call out any information that would be helpful to the driver. Short and accurate communication is best. Calling out other vessels, location, speed, and heading are all important pieces of information. As the driver, balance what your crew says with what you see and hear.
If you do not have a crew member dedicated to the radar display, have no fear. Continue to rely on your senses, keep your eyes scanning the area around you, and look at the radar display about every 30 seconds. Remember to keep your eyes moving to gather the greatest amount of information.
GPS is a great tool to help you stay on course and, in some instances, get you back to where you came from. As with all electronics, get familiar with the system before you absolutely have to use it. Even though GPS devices have greatly improved over the years, they still can be inaccurate within a certain distance or speed, so become familiar with the limitations of your device before you need to depend on it.
Some GPS systems allow you to see where you have been. In low visibility, use the path you set going out as a guide to get back. If this is not an option, you can set waypoints and use them to navigate. Look and listen for changing conditions, and use the boat's electronic systems as a reference. Keep enough speed to allow the GPS to read what direction you are heading in, but not too much that it would be hard to avoid an obstacle.
Most boats have an onboard radio, but just in case, one crew member should bring a VHF on any vessel. A radio is another good tool to use in low-visibility conditions. If you can supply the information, radio your boat name followed by your position (latitude and longitude), course direction, speed, and boat type or size. Communicate in short and clear phrases. This lets people in the area know where you are and what to expect. We recommend you use channel 16 or 13 to relay this information.
Review the USCG Rules for navigating in low visibility.
Navigation Systems and Racing
This information is for boats equipped with navigation systems that can create waypoints. Before the start of the first race of the regatta, make a waypoint at the boat end of the starting line and one at the middle of the bottom gate. If you have time and the visibility, sail up the course and ping a waypoint approximately where the mark and any other relevant marks are. If you don't have time or visibility, listen to the race committee for the bearing and distance to the top mark. This information will allow you to make a waypoint in the direction and with an approximation of the distance to the top mark.
When you have these points set, race exactly as you would with full visibility. The only change is to be more aware of other boats, traffic, and potential obstacles. Keep everyone's head on a swivel, and always be ready to avoid something. Play the shifts as you would in a normal race while relying on your navigation systems to keep you on course.
If you can, it's a good idea to have someone down below watching the navigation system and calling distance and time to the lay line. Communicate in short and accurate statements with the navigator, tactician, or skipper about what they are seeing.
Sailing with an electronic compass can also help you find the course if your boat is not equipped with a navigation system or GPS. The trick to finding the top and bottom mark when sailing in low-to-moderate visibility is to time yourself as you sail away and toward the rum line of the course. As soon as the race gun goes off, commit to one tack. Time yourself: five minutes on starboard or port depending on how the start goes, tack, and then five minutes on the other tack. In doing this, you've essentially gone five minutes away from the rum line and then back to about the middle of the race course. Do this again for four minutes, then three minutes, then two minutes, then one minute, and finish up with 30 seconds. Avoid trying to one tack the upwind beat; the chances of finding the top mark are very slim if you do this. By utilizing the 5,4,3,2,1 method, you have spent approximately 30 minutes sailing. For lasers on a one-mile course, this might be the perfect amount of time to get to the top mark, but for faster boats, slower boats, shorter distances, or longer distances, this timing may need to be adjusted.
Turning Around the Mark and Heading to the Bottom Mark
The bottom marks should be easy to find in a boat sailing almost directly downwind. The race committee probably posted the course direction before the race so if the course was set at 0, the marks should be at 180. If you're sailing with a compass, sail downwind at around 180, and you'll be able to find the bottom marks. For boats that enjoy the same tacking angles as gybing, use the same method as the start of the race, but spend less time on each gybe. Boats typically move faster downwind, so take that five-minute benchmark and cut it down to four or two-and-a-half, and scale it down from there, gybing every 15 to 30 seconds by the bottom of the course. You should be able to find the bottom mark using these methods.
When racing in low visibility without instruments, you can't see where you’re going or where you’ve been−a tough task to be sure. You need a combination of luck and skill to guide you to the next mark. It’s a little like sailing in survival mode: tactics are not as important as getting to and around the next mark. In these conditions, it's more important to stick to the 5,4,3,2,1 method than to deal with traffic or other boats affecting your race. When in doubt, duck a boat to continue on with your timing, and if someone tacks in your face, clear yourself and continue on your previous tack. Remember to adjust the timing for how fast or slow your boat is going as well as for how long or short the course is. In these conditions, the race typically starts with clear skies and ends with a bit of fog. The race committee usually won't start a race in limited-to-no visibility and with boats that don't carry electronics or compasses, but they will finish a race. Do what feels best. If you're on a reach and the mark disappears, sail the angle that makes the most sense and you'll probably end up at the mark or near it. Trust your instincts and sailing ability to get you to the right spot.
If you haven't checked it out already, here is Part I of "When the Fog Rolls In."