Why is the compass so important?
“When we are proposing a system for a vessel one of the absolute keys is to make sure it has a good heading source, a good compass,” says Laurie. “Yet when people consider a radar and/or system upgrade, the compass is unlikely to be at the top if their list. They will often be looking at upgrading in stages rather than as a complete refit, perhaps spanning over a few seasons with the focus on say a new display, a new radar or a head unit.
“This is completely understandable, not everyone can or wants to do everything all at once. But the chances are that the compass, which is usually located out of sight under a bunk at the back of the boat, will be overlooked. Yet this one unit plays a huge part in the accuracy and general performance of many other functions. The compass might be out of sight and out of mind, but it’s playing a big part in your instrumentation system. Even so, it is surprisingly common to find that the compass in an otherwise new system aboard a customer’s boat is actually fifteen years old and will not be up to scratch for the job.
“So, unless you can be certain that bearings are accurate it will be hard to be 100% confident in identifying a specific target on your radar which clearly negates the main reason for having one. And while your radar is still going to be able to paint, without a decent heading sensor that is both accurate and can understand the motion onboard your boat and make allowances for it in real time, you are not going to be able to use your Velocity Tracking feature or rely on MARPA tracking. Again, this takes away another of the key reasons for having a radar.”
Like so many areas of modern electronics, in recent years marine instrumentation technology has advanced significantly and has led to the development of highly accurate compasses that can assess and compensate for a boat’s motion to a degree of accuracy that simply wasn’t possible, or affordable for most leisure craft before. So what are the broad options and key considerations? Craig explains.