Advantages of Having a Tablet Onboard

 June 2016. Approaching Shallotte Inlet, North Carolina. "These markers look different from our chart. And the notes say we should hug the green, but was that the old green and now the new green is OK? We can't get too close to the red side, the notes say there's only 3 feet there. Is the current pushing us? Should we speed up to fight the current or slow down so we hit the sandbank slowly?" Bad times.

February 2020. Approaching Shallotte Inlet, North Carolina. "How's it going?" "Fine, I can easily see the shallows on AquaMaps. We're keeping our speed up to fight the current and I'm not worried about the sandbanks." Good times. 

It has become pretty common to see tablets used in place of chart plotters on cruising boats, but did you know that a tablet is also the perfect companion to your chart plotter? Once you get the hang of how the software and apps work together, you can use the tablet for your planning before you set out on a trip. While traveling, the tablet makes a great backup. Plus, most of your favorite cruising guides integrate with navigation apps, making it easier than ever to see hazards along your route or pick out marinas or anchorages. Here's a look at the way we've been using our tablet onboard Dulcinea.

The Importance of a "Real" Chart Plotter

So why not use your tablet as your primary chart plotter and save a few thousand dollars? For boaters that stick close to home, it might work fine. But modern chart plotters are actually MFDs or multifunction displays. This one display shows and controls nearly everything onboard. They are usually the only way you are going to be able to view radar and sonar data if you have those items on board. 

NMEA2000 networks are easy to set up, and they enable you to plug in pretty much anything to your chart plotter. Newer engines offer NMEA2000, so you can view your engine instruments on your chart plotter. With an NMEA2000 fuel gauge and fuel flow sensor, you can view your real-time fuel range. AIS and even regular VHF radios now connect over NMEA2000, enabling you to see other vessels, get alarms for hazardous targets, and even initiate a DSC radio call directly from the chart plotter. Sailboats with NMEA2000 wind instruments benefit from lay lines and sailing data displayed right on their charts.

The chart plotter is your boat's primary computer and control station. Yes, it's possible to tap into NMEA2000 networks via wifi or USB connects and view the data on your computer. There are many great apps on the market to enable your tablet to do the same. But they all have weaknesses, and none of them are hardwired in. We find wireless connections to be glitchy, and sometimes the tech just doesn't work as quickly or as flawlessly as we'd like.

And of course, tablets have disadvantages too. They can be hard to see in direct sunlight. Some of them shut down when their temperature rises too high, which can happen quickly in the sun. They are also not waterproof, and even with waterproof cases, their touchscreens do not work well when they're wet. And their user interface isn't optimized to be used from a bouncing boat.

And then there's the reliability problem. Your chart plotter was designed knowing that it's a valuable piece of safety equipment. Your radar can't and shouldn't lose a network connection in the middle of the night in a tight channel. The software must be stable and tested, and it must work flawlessly with the hardware that you have installed. For this reason, you aren't going to find many third-party apps on chart plotters. 

So clearly, we believe that cruising boats should have a high-quality, name-brand chart plotter onboard. So what's the point of having a tablet too?

Some Benefits of Tablets

In my mind, once you understand the advantages of the chart plotter mentioned above, the tablet's greatest strength is its ability to view any number of different brands of charts. Your chart plotter comes loaded with some charts, and you might decide to load a new set as you cruise around. But this becomes pretty cost-prohibitive since new areas of charts are usually between $150 and $300 each. We don't know too many people that update those charts every year. We don't, because we don't think those charts change as much as they should.

But having a tablet means you can always have the latest charts too. There are numerous apps, most in the range of $10 to $25 per year, that give you access to the best charts out there. Some of the apps enable you to see data that you just can't view on any chart plotter (more about that below).

Another great benefit of having a tablet is the ability to use it in conjunction with your chart plotter. All of the major chart plotter manufacturers now include Wi-Fi in their models, and they have companion apps that you can download. With the app, you can view the charts in your chart plotter from the comfort of your salon, making it easy to plan for the next day. You can create waypoints and routes on the tablet (which is usually easier to operate in the planning phase) and then send the data right to your chart plotter for the next days trip.

And while the tablet is far more likely to fail than your chart plotter is, having two navigation instruments is never a bad thing. If the chart plotter got buggy all of a sudden and didn't cooperate, you have a backup tablet ready to go.

Getting a GPS Position on Your Tablet

Note: The info below applies to Apple iPads. We're not familiar with Android tablets, but it's probably a similar system.

Each size of the iPad is sold in two basic models: Wi-Fi only or Wi-Fi +cellular. The Wi-Fi-only tablets are about $150 cheaper than their cellular counterparts. A Wi-Fi-only tablet does not have a built-in GPS chip.

The Wi-Fi +cellular tablet is a great choice if it's the only device you have that you use online. If you want the cellular data to work, you'll need to pay for service as if it were another cell phone line. Onboard Dulcinea, we have a mobile hotspot that keeps all of our devices online with only one line. We really have no need for a cellular iPad, so we go a different route. For what it's worth, if we did have a Wi-Fi +cellular iPad, the GPS chip would work even if we didn't activate the cellular service.

Since we have Wi-Fi  only iPads (yes, we have collected a selection of these things!), we need to use an external GPS device. Our current favorite device is our Garmin InReach Mini, which connects to one device at a time via Bluetooth. It provides a super-accurate GPS position for all of our different apps, and since it connects via Bluetooth, we can still get online via Wi-Fi. And of course, the InReach offers much more than just GPS position: it's a satellite messenger and tracker too.

In the past, we have also connected to the chart plotter Wi-Fi to provide a position to the tablet. It depends on the chart plotter, but this might only work with the one app that is made by the same manufacturer as your chart plotter.

You can also buy a standalone GPS device for your tablet. Dual and BadElf both made Bluetooth GPS devices that will work fine, but you'd have to confirm with each app that you're going to use it with. In my experience (specifically with the InReach), the device manufacturer can't confirm what other apps might work. And even if they do work now, will they work after the next software update?

What We're Using This Year on Dulcinea And How We're Using It

We change this up when we discover new and better ways to do it, so I'm titling this section "what we're using this year" for a reason. Some of the details might change from time to time!

Primary Chart Plotter–B&G Zeus3 7-inch with a C-Map North America chart chip

Other equipment connected to the Zeus: B&G 4G radar, wind instruments, sonar, Vesper AIS

Tablet–Apple iPad and an iPad Mini (both very old versions!) 

Bluetooth GPS unit–Garmin InReach Mini click for more information.

Current Favorite Apps

C-Maps Embark

This is the B&G provided app. It's, unfortunately, a little clunkier than the Garmin system we used before, but it works fine. In the Embark app, you can set up routes and waypoints. They are synced online to your free Embark account. You then get your chart plotter online, and once logged into that same Embark account the waypoints and routes will be synced.

We liked the Garmin setup we used a few years ago better simply because it didn't require being online. If we wanted to make a route with this B&G setup in the middle of the ocean, we'd have to do it locally on the chart plotter.

Navionics Boating

Navionics (now owned by Garmin) has an excellent reputation for making nice charts. The app is helpful and user-friendly too. If we bought a Navionics chart chip for our B&G plotter, we could do our planning and route directly to the chart plotter with this app. But we're cheap. When it came time to buy a chart chip, we opted for C-Map because they use Explorer chart data for The Bahamas (where Navionics has an earned lousy reputation).

Since the app only costs $30 per year, you could easily cover the cost of a tablet and the app by not buying a Navionics chart chip at $200-300.

The Navionics charts are nice, but they have not proven themselves to be very helpful. We like the app for planning, and we like that it overlays ActiveCaptain reviews and anchorage data. The Navionics Sonar Charts are a neat addition. The charts are "augmented" by user sonar data. It seems pretty inconsistently implemented so far, and as the end-user, we are never able to figure out the quality of the data we're viewing. The Sonar Charts look very different, but that's mostly due to the presentation of depth contours. How they came up with some of those contours is still a bit of a mystery to us. When it comes to navigating in shallow or tight spaces, we're not fans of mysteries.

Aquamaps Master

If you are navigating the ICW, this app is simply a must-have. Even if you don't have a tablet, I think you should buy one so that you can get this app before you set out down the ICW. Here's why.

There really isn't very good charting on the ICW. The NOAA government charts show the channel and the "magenta line." All of that is an estimation of what is supposed to be there–the projected depths and where it is supposed to be. There are numerous trouble spots and inlets that you will pass where the sandbars and mudbanks never got the memo of what they are "supposed" to look like. Some of them change so often that the buoys are moved every few weeks, and even then, they might be off station.

A few years ago, we discovered that you could download the most current Army Corps of Engineers hydrographic surveys. The ACOE has a fleet of boats that are continually mapping the bottom of inlets, harbors, and yes, the ICW so that they know where should get dredging next. If a significant storm passes, they'll have the new survey up in a matter of days. It's all available on their website.

As handy as that is, this information downloads as a PDF chart that doesn't easily plug into a charting program. This is where Aquamaps Master shines. The app overlays the ACOE surveys right on the map, with your real-time position shown. You can easily navigate the trickiest parts of the ICW with this.

You still have to keep an eye on current conditions, of course. The surveys in trouble spots might be a year old, which means there are lots of chances for things to move around. Even still, we've found them to be the most accurate and most reassuring chart product available for the ICW. The high quality of these surveys is one reason we give Navionics Sonar Charts a solid "meh."

The app also offers Explorer charts for The Bahamas, a definite plus. And you can overly both ActiveCaptain and Waterway Guide data for bridge, marinas, anchorages, and inlets, which is very handy when you're looking for nightly stops or places to explore.

Waterway Guide Explorer

Waterway Guide's website is a powerful planning tool. Ever since Garmin bought Active Captain, the loyal troop of reviewers and participants there has dwindled. Many, it seems, have migrated to Waterway Guide Explorer with their reviews and comments. Bob423 on Fleetwing, possibly the most trusted expert on ICW trouble spots, now updates Waterway Guide's website continuously. His blog is worth checking out too.

One advantage to the Waterway Guide Explorer site is that reviews and comments are moderated by the folks at the Guide, who make sure that reviews are helpful and confirmed. Problems are researched and vetted to make sure the comments are useful to everyone and that they add to the value of the website. Sometimes on Active Captain it can be a challenge to filter out the noise, and Waterway Guide has addressed that problem.

Google Maps

My favorite use of Google Maps is to find restaurants close to the anchorage. We love the satellite view and the businesses that show up on it. We find beaches to land on and places to hike. We also always look at marinas before we approach so that we have some idea of where the fuel dock is and what sort of docking planning and approach we might need to make.

Conclusion

For us, you can never have too many charts. Having a tablet onboard means that you can have access to pretty much every brand of chart for a very low cost. The tablet makes it easier to set up routes and do planning in advance. For us, that makes the iPad one of our favorite pieces of navigation equipment. 

What system have you found works best on your boat? Let us know in the comments below!