Staying on course with Wi-Fi


Enjoying fingertip wireless access to the Internet while sailing in coastal waters has become a way of life for many sailors. At the very least, we depend on our cellphone service providers to make sure we stay in touch around the clock. If we are near a Wi-Fi transmission point, or if we pay the high cost of worldwide Internet service while sailing offshore, our crew enjoys the benefits of connectivity wherever our vessels roam. With or without such worldwide Internet access, we can still enjoy the benefits of Wi-Fi connectivity within our own networks while afloat.

Most of the material we find on marine Wi-Fi is focused on Internet access provided through an onboard hot spot, which is connected to a high-gain antenna capable of receiving Wi-Fi signals up to several miles way. Many coastal cruisers sailing near large population centers are able to use their smartphones as hot spots but often with less connectivity.

In addition to its place in personal electronics for voice, text and Internet communication, onboard wireless connectivity is also growing in another critical role aboard cruising vessels: connecting into navigational electronics without the need of an Ethernet cable. Instead of having to clamber out to the cockpit in the middle of a raging gale at 0200 to check the chartplotter, that job can now be made easier through Wi-Fi access on an iPhone, iPad or Android device anywhere on the vessel.

Wireless navigation basics
The core of an integrated wireless navigation system is, in most cases, the chartplotter. Readings on vessel speed, heading, GPS position, weather data and engine panel are brought together via a Wi-Fi or Bluetooth antenna system mounted separately or embedded in the chartplotter, transmitting readings to a remote hotspot provided by the manufacturer or to a smartphone or tablet device.

An IKC wireless router by Digital Yacht.

Courtesy Digital Yacht

Generally, in a wireless navigation network all the components — except the smartphone or tablet — are built by the same manufacturer. This ensures 100 percent compatibility among the various devices in the array. The user installs an app on the smartphone, using the device to enter waypoints into the GPS, course alterations to the autopilot and other commands to control the vessel’s trajectory and performance from any point on the vessel. The wireless setup may use an external router to transmit signals from a central location to remote points on the boat, an important capability to consider on larger yachts.

Remote navigation access frees up skipper and crew to move about the craft, allowing them to multitask between navigation duties and attending to other chores. It enables users to alter vessel speed and, if the ship’s autopilot is integrated into the mix, the heading as well. Imagine picking your way through a maze of coral in the South Pacific while standing at the bow — or in your boatswain’s chair halfway up the mast — controlling engine speed and vessel heading with your iPhone. Having smartphone access to the nav system is like having an extra crewmember.

Internet connectivity
Online cellphone service providers such as Verizon, AT&T and T-Mobile are growing in their capacity to provide telephone and Internet access farther offshore, sometimes up to 10 miles, with their coastal cell towers. But this access is patchy at best, with lots of dead zones outside of large urban areas. And in foreign ports, we can forget about this access unless we want to pay roaming charges.

If you are near an outlying anchorage, resort or foreign marina where Wi-Fi service is offered to patrons, however, a highly sensitive signal amplifier can act as a hot spot and provide your crew and passengers with Internet access through a router. And let us remember, it is not just email and social media we are seeking, but also the latest NOAA weather reports to help ensure a safe voyage when we leave port.

A router installed on the vessel can be configured to transmit data from the chartplotter or from a Wi-Fi transmitter on shore, depending on the router and the needs of the crew. While Internet communication is certainly a priority for many of us, the focus of this discussion is centered on our vessel’s capacity to communicate with itself, routing critical data necessary for the safe operation of the ship while underway. A small number of manufacturers of marine navigation technology are leading the way in wireless data sharing aboard cruising vessels.

A diagram from Digital Yacht showing how smart devices like engines can use wireless to talk to a boat network: The boat engine is interfaced to the Signal K gateway and onboard iPad used to display engine status, fuel flow, optimized economy, etc. Data is stored on the iPad and uploaded to the Cloud server when required. Data is analyzed by the engine manufacturer and a custom service profile is developed.

Garmin control
Garmin’s GPSMAP 7408 was designed with cruising sailors in mind. The chartplotter features an 8-inch widescreen display and operates within a Garmin Marine Network, plus NMEA 2000 and NMEA 0183. The chartplotter comes with internal GPS that gives position updates every 10 seconds.

The 7408 allows you to build a network comprising a wide swath of components in your navigation array: radar, autopilot, sonar, thermal cameras and more. The chartplotter has a rotary knob, joystick and keypad control, ensuring an ergonomic platform for that long early-morning watch.

Garmin’s GND 10 black box interface ties together Nexus instruments and sensors with the Garmin network. The one component capable of wireless communication within the network is the gWind Wireless Transducer, an anemometer running on a self-contained solar panel and replaceable long-life batteries. The obvious advantage with gWind is the elimination of the power and data transmission cables from the mast, eliminating extra installation work and weight aloft.

To access and control the 7408 chartplotter through your smartphone device or tablet, you can download the Garmin Helm app from the Apple App Store or Google Play. In order to plan sailing routes on your mobile device and transfer them to your Garmin chartplotter, download BlueChart Mobile, a free app from the App Store.

Garmin makes available its own wireless receiver and hot spot, the Garmin Marine Wi-Fi Adapter Kit. The complete kit includes a Wi-Fi adapter, omni-directional antenna, wall mount holster, power cables and Power over Ethernet (POE) injectors, along with a Garmin Marine Network cable and coupler.

The Garmin GPSMap family of MFDs.

Courtesy Garmin

Furuno Navnet TZ Touch
The Navnet TZ Touch system from Furuno provides radar, GPS, Fish Finder, AIS, weather information and more through a “multi-station integrated navigation network.” TZ Touch allows you to build a system based on your navigation needs and personal style using a “multi-touch interface,” which allows for what Furuno boasts as “intuitive control of the whole system.”

The TZ Touch network is built around a chartplotter that can be accessed through pinch-to-zoom control or via smartphone and tablet apps using iOS or Android devices. Furuno’s unique system also offers connectivity to hot spots, allowing you to download useful updates, including real-time weather data from the Internet.

By accessing the TZ Touch system through your smartphone with the NavNet Viewer App, you can monitor your vessel’s GPS coordinates, heading, speed and depth sounder, and operate the chartplotter’s array through your iPhone or Android device.

Another useful tool, Furuno’s weather station comes free with NavNet Touch, allowing you unlimited access to worldwide weather forecasts around the clock. Simply select the geographical area, time period and type of data, then select how you wish to receive the file and the NavNet TZ Touch will provide a weather forecast of up to 16 days. 

The Furuno NavNet  TZ Touch L15F can integrate a multi-station nav network.


Raymarine eS Series MFDs
The Raymarine eS Series chartplotters offer a powerful array of monitoring systems, all accessible through the RayControl mobile app for iOS and Androids or through the Raymarine RCU-3 Bluetooth wireless remote.

Available with a 7-inch, 9-inch or 12-inch screen, this series of navigation platforms offers pinch-to-zoom control of charts from Navionics, C-MAP from Jeppesen, and Raymarine’s growing catalog of LightHouse charts.

The mid-range 9-inch screen version is available as either the eS97 multifunctional display with Clear Pulse Sonar or the eS98 display with Raymarine’s CHIRP DownVision Sonar. CHIRP, or Compressed High Intensity Radar Pulse, was developed by the U.S. Navy to enable enhanced deepwater penetration and detection of sea floor detail.

The expanded package, available for the ocean sailor who wants it all, includes the multifunctional display, a 10-Hz GPS/GLONASS internal receiver for rapid chart position updates, autopilot monitoring, an optional sonar module, video monitoring of up to 10 onboard cameras, engine integration and digital switching for lighting, climate control, navigation, entertainment, security and other systems.

The panel also features an engine monitoring screen with a virtual display of analog meters, accessed through a NMEA 2000 connection for Yanmar and a number of other engine manufacturers. The weather screen enables graphic weather overlays and reports from Sirius XM, but this capability is limited to the navigable waters of North America.

The Raymarine e59 can be controlled with a Bluetooth remote.


For added safety, particularly in cruising grounds dotted with exposed rocks or floating obstructions, you can add a thermal night vision camera so you can negotiate your way through the debris field on a moonless night. Thermal vision can be a lifesaver when a crewmember or pet falls overboard. The camera’s “slew-to-cue” capability “cues” the camera on the target and automatically keeps the subject in view until the operator resets the camera.

Managing signal interference
The advantage of wireless navigation connectivity is so empowering, you would think boat insurance companies would offer special discounts for vessels with wireless navigation. However, Wi-Fi networking can sometimes pose its own brand of limitations in the form of signal interference.

Interference in wireless systems has the potential to distort or block data transmission anywhere along a signal’s path, be it in the navigational component itself, the router or the atmosphere through which the signal travels. Without adequate protection, electrical noise in the boat’s navigation system can interfere with individual devices or interrupt vital radio contacts in an emergency situation. Noise from electrical components might disrupt the autopilot, GPS, radar or chartplotter, setting the vessel off course and potentially exposing both vessel and crew to danger. When a vessel can no longer “see” where it is going or provide correct steerage, particularly in rough weather, it can hit submerged obstructions or capsize in heavy seas.

A common source of interference is either the propulsion engine alternator or a separate generator set, both of which have alternators that use rectifier diodes to convert AC to DC current. These diodes often produce an electrical whine that interferes with radio transmission and reception, as well as sensitive electronic navigation equipment.

The Digital Yacht iKommunicate unit is a Signal K gateway that allows many devices to join a boat network.

Courtesy Digital Yacht

Fortunately, you can purchase an alternator noise filter for about $20, or you can make your own noise protection device to eliminate or severely reduce noise. The design of your device will include either an inductance coil or a capacitor with a ground connection. Search for “alternator whine protection” online for an inexpensive solution to alternator electrical interference. 

Other sources of noise may be rooted in atmospheric conditions, an alternator in a wind or hydro generator, depth sounders or small electric motors, such as those found in blow dryers, electric shavers and pumps.

Most late-generation wind and hydro generators contain sealed magnets that prevent spark and its resulting noise. More difficult to tame are motors in small appliances; the best solution is simply to turn them off. But if it’s a duel between pressurized water and the autopilot, the choice is obvious — heave to and shower!

Also, attempting to network navigation components from different manufacturers may cause some signal crossover or incompatibility, resulting in noise or compromised performance. For specific situations and solutions, you will need to check manufacturer websites or hire a technician to resolve the interference.

Making a complete break from wind vane self-steering and paper charts and jumping into the world of autopilots, chartplotters and wireless networks taking over at the helm is a giant step for some of us. But a pinch-to-zoom networked monitor is a powerful stress-reducing alternative to traditional technology.

Bill Morris is a marine writer and the author of the new book Sun, Wind & Water published by Seaworthy Publications.

By Ocean Navigator