Click here to see what CHIRP is.
Because of the price point and because I’ve had great luck with Garmin before – there was absolutely no competition.What really makes this unit a homerun, though, is that it does everything…
I have a simple Raymarine depth instrument. That’s great for poking around anchorages and knowing how much scope to let out when I anchor. But it’s not great for finding fish, seeing the composition of the bottom, or identifying reefs and wrecks on the bottom. Being able to see a sonar image of the bottom is something I missed. So a huge bonus to getting this Garmin unit was the ability to add a transducer for redundancy, but also to (finally) be able to see the bottom as a means to find fish and structure and dive sites. A huge improvement. I didn’t go with a CHIRP system due to the expense – I don’t need the ability to see a grouper hanging over the bottom in 2000 feet of water (yet).
For navigation I currently use my iPad Air with SeaIQ and the CM93 charts. The iPad is great (more on that later), but I wanted redundancy in GPS/chartplotting and it’s really nice to have a purpose-designed tool. As if that wasn’t benefit enough, now I can overlay radar on charts and with a couple flicks of my fingers, watch the bottom in 2 different sonar frequencies.
Finally, the unit talks to all of my other electrical doodads onboard. It’s wired, through NMEA 0183 to my Standard Horizon GX2000 VHF. It’s wired through NMEA 2000 to my Vesper Marine XB8000 AIS system.
The unit itself is a small (relatively speaking) and handsome touchscreen. It comes with the ability to flush-mount or gimbal it. I chose to gimbal it, to avoid cutting big holes in my cockpit dash and to keep the screen closer to me (easier to see/use). The menus are intuitive, in typical Garmin fashion, and the connections are all marine-grade – meaning they screw together and have O-rings that keep water out.
When I purchased the unit, I purchased it as the radar/GPS combo (GPSMap 741sx and GMR 18HD), and then purchased the NMEA 2000 starter kit and the in-hull transducer separately. Installing the radome itself was a PITA because I had to climb the mast in a rolling anchorage – but Garmin did us a HUGE favor by making the radome backwards-compatible with other 18” radome mounts – meaning my old Raymarine radar mount screwed directly into my new Garmin radome. That’s something you don’t see very often, a round of applause to Garmin.
Installing the GPSMap 741sx was simple. Finding where to mount it was the hardest part. The good news is that the 741sx has an internal GPS, a plug for an external GPS antennae, and it can pull GPS coordinates from other networked devices (for me, my Vesper XB8000 AIS). So there was no reason to run another GPS antennae or pull more wire through the boat. Here’s what the bottom of the anchorage looks like in CTG – split screen showing two sonar images, one in 50hz and another at 200hz.
Connecting the NMEA 2000 and NMEA 0183 to the unit (to network everything) was remarkably simple. I really appreciate the plug-and-play nature of NMEA 2000. To run my NMEA 2000 network I simply needed to plug my Vesper Marine XB8000 and Garmin GPSMap 741sx into the NMEA 2000 backbone – and then run a power cable to the network. Too easy. NMEA 0183 was a little more hazy because I had to crimp wires and decipher diagrams from Standard Horizon and Garmin – but I managed to do it in under an hour.
The transducer installation was trial and error. I wanted the transducer as far front as possible, and I wanted it in the starboard hull (opposite my Raymarine transducer). The design of my owner’s version Lagoon 380 made that difficult – but after a 1/2 day of playing with it we got it positioned in an acceptable spot. To finish the installation of the transducer, we needed to grind the inside of the hull (below the waterline) to bare fiberglass, and then use 3M 5200 to attach the transducer housing. At that point we simple let the 5200 cure, filled the housing with antifreeze, and plugged the transducer into the housing. Not difficult at all, and it sure beats a thru-hull transducer which means hauling the boat out of the water to drill another hole under the waterline.
The biggest hurdle in the installation was mostly my fault – I needed more cable for both the radar data and for the transducer. Of course, I installed this in Colombia, so it wasn’t as simple as walking to West Marine and picking it up. It took a couple of weeks to get it here.
With everything installed, hooked up, and powered on I couldn’t be happier. For less than $2,5000 (all in), I have radar, a bottom-machine, and redundancy in depth/GPS instruments. All on a color touch-screen that makes using it a pleasure. Of course – the real test will come as I use the system over the next 5-10 years, but for now – all’s well.
For smaller recreational boats, I can’t see the need for anything else. Garmin’s 741sx does it all without sacrificing usability or breaking the bank.