Common sense tells us we need to be peripherally aware of what is occurring on the water around us, whether we are hugging the shore or undertaking a major offshore passage. However, some small vessels still cross oceans without the aid of radar or AIS technology to ensure some level of safety from nearby vessels and uncharted obstructions. Cost, lack of reliable information and an aversion to technology in general conspire to keep some sailors from enjoying the feeling of safety that comes with knowing what’s out there.
In the February online issue, we discussed the comparative attributes of AIS and radar. To sum up, AIS works only if other vessels in your vicinity are equipped with the same capability. It cannot warn you of small fishing vessels plying the coasts of developing countries, or derelict ships or outcroppings of rocks. This is why so many sailors depend on radar, which can help you identify vessels and obstructions not detected via AIS.
For skippers on small vessels, say under 35 feet LOA, the two main barriers to radar are price and amperage draw. A full installation of a radar system costs significantly more than an AIS system, especially now with AIS integrated into some VHF radios. And operating a radar, even at a miserly 1.3 amps (150 mA standby) for the smallest units, not including the monitor, may still be more than some small boats can afford to expend from their minimal battery storage.
Other concerns are finding a place to install the dome: It needs to be high enough to see past the tops of waves yet low enough to prevent excessive weight and windage aloft. Also, installing the unit should be a fairly straightforward procedure, the monitor must be easy to use and understand, and the various components should be capable of being connected through such interfaces as NMEA 0183 or NMEA 2000.
So where does this leave the small-boat sailor who wants to enjoy the advantages of radar? Assuming the vessel has at least an 8D deep-cycle house bank with a minimum 400 reserve minutes — along with dependable alternative energy charging sources — a handful of small radars now on the market will serve well.
A prime example is the Simrad Broadband 4G Radar, which is packed with features for the best level of safety and user-friendly components to be had in any small-boat radar in its size range. Parent company Navico offers the 4G as the world’s first dome radar to feature “beam sharpening,” which allows you to control the level of target separation to sharpen each image on the monitor as needed.
When the target is close to you, especially if approaching at high speed, you can use the Simrad 4G’s high-speed (48 rpm) mode for instant updating at distances of less than 1 nautical mile. The unit’s MARPA target tracking capability allows you to track up to 20 targets in dual range mode, although this requires the addition of a heading sensor. The 4G has a maximum range of 36 nautical miles and consumes 1.67 amps when cycling and .24 amps in standby.
Since there is no need to open the dome and the installation of power and network cables is fairly straightforward, there is no need to hire a technician to install the system, saving you a small fortune in labor.
A bit more affordable is the Garmin GMR 18 HD Radome, which offers MARPA target tracking when combined with an optional heading sensor. With the unit’s 5-degree beam width, the 18 HD provides what Garmin claims is “the best weather penetration and target definition in its class.”
Once the 18 HD is connected to the Garmin Marine Network, you may use the radome with any network-compatible Garmin chartplotter to serve as the radar monitor. To enhance your situational awareness, you can overlay the 18 HD’s radar image onto a Garmin chartplotter screen, giving you the best possible integrated navigation view that technology can offer.
Although radar still isn’t rock-bottom cheap, it is in a range that the average cruiser can afford — not only in terms of price, but in terms of amperage draw as well. AIS is great, but nothing beats the security that comes with a dependable, high-quality radar system.