Big Ideas for the Small Boat


Boaters today have a lot of ideas about what their tenders can do.
Here’s how to help your little boat exceed expectations.

Electronics on a tender

Count yourself lucky if you’ve never dunked the outboard of a small boat in the labyrinthine coastal waters of the Inside Passage from Alaska (don’t ask how). Bonus points for doing it during the shoulder season, when other cruising boats are fewer and farther between.

Obviously the scenario turned out okay as I’m writing this today with all my extremities intact. Plus the water there is not nearly as cold as you’d expect, something of a delightful, if damp, surprise. Still, that little 25-horsepower Yamaha miraculously fired right back up (somehow) and ran well enough to drain the tender (a 13-foot Boston Whaler) once we offloaded the entire crew. That’s right, the entire crew. No one was left on the big boat. And while that water was warm, it wasn’t so warm you’d want to swim for it.

It’s these times—when you find yourself quite specifically presented with answer after answer to the heretofore rhetorical question, What could go wrong?—when communications and gear can make all the difference between a cocktail in the cockpit while enjoying the view and a damp evening on the shoreline, tinkering with the outboard by (if you’re lucky) firelight and preparing a mental list of things to carry in the tender from now on.

The electronics on a cruising boat serve both to simplify and amplify your cruising experience. The electronics you carry on your tender should do the same thing. If it isn’t completely obvious, safety must always be the first consideration.

Communications & Safety

“I would suggest any tender carry a handheld VHF with built-in DSC and also GPS in it,” says Hugh Lupo, partner owner of New England Marine Electronics ( “Make sure to program the MMSI number into it.” As we’ve mentioned in the past, the Maritime Mobile Service Identity number, or MMSI number, is the key to making the most important functions of a DSC VHF work when you need them most.

“Programming the MMSI number in gives you all the functionality,” Lupo says. “In an emergency, you can alert Rescue 21 by pushing the emergency button, and they will know immediately where you are. While you may not be the main vessel, they will know where you are because they can track to that radio by requesting its position. They can do that at Rescue 21, and they can do that from aircraft or from the surface vessel or any vessel out there that has DSC capability.” The mothership can find the vessel too, as long as it has a properly installed DSC VHF radio with an MMSI programmed in.

As tenders grow larger generally they will carry a fixed-mount VHF, but it’s critical to remember to input that MMSI number and connect the unit to a GPS in order to enjoy the full safety functionality. A fixed-mount VHF will need an antenna. The options include a 4-foot stick or even an antenna designed for a sailboat. While these shorter antennas may limit the range of the VHF keep in mind, this is a boat meant for use as a tender. A larger antenna may suffer damage from the davit or the garage, and therefore a smaller antenna that will stay in working condition is a far better choice.

Another piece of gear to carry: a personal locator beacon (PLB). “A PLB worn on the lifejacket of the person in the small boat, or at least always on board is important,” Lupo says. “Even if somebody’s having a heart attack you can deploy it. A lot of guys think it’s only for when you’re sinking. But any time there’s a medical emergency: If somebody is hurt really bad, or cuts himself and is bleeding like hell, you just kick it off.” Getting around by boat takes time. Even if you were to bring the injured person back to the mothership, an early distress call can make all the difference in receiving timely help. Alternatively, a handheld satellite communicator with GPS, such as the DeLorme InReach (, permits two-way texting with the mothership or rescue personnel beyond cellular or VHF coverage and includes a PLB-like instant-distress function.

MMSI: Eight Is Enough

The Maritime Mobile Service Identity number, or MMSI, you program into your tender’s VHF should match that of the mothership. But in other countries, such as in Europe, we’re hearing of a trend that has begun to put an 8 in the first number position, then enter the mothership’s number, leaving off the last digit. That format denotes a tender. Again, in the U.S., we use same MMSI for all boats and portables that travel as a unit. Stay tuned for updates. But in the meantime, please enter MMSI numbers whenever your electronics call for them. This powerful system could save a life.

GPS, Charts, and Sounders

Any cruiser knows the value of GPS, and electronic charting makes even more sense on small boats since paper charts can be challenging to use (though we recommend all boats carry a paper chart of the area). It’s key on boats of all sizes for crews to keep track of where they are, both on their own and in relation to the mothership.

Of course helm space is at a premium and the idea is to get the most functionality you can out of one small screen. “We usually use the small Garmin,” says Jon Schimoler, owner of Voyager Marine Electronics ( “It’s mounted in the dashboard and it’s all self-contained and has a transducer for depth. We try to match the tender system to what’s on the main boat—use the same manufacturer—so its operating system is the same, because a lot of different people may need to use the boat. Size is a big consideration. We’ve been pretty heavily into the small Garmins—one called the GPSMap 547 in the other called the GPSMap 741 with charts and built-in GPS antennas.”

Any multifunction display that would be installed on the helm of a small boat today is waterproof. The screens themselves have improved in leaps and bounds as well. “They’re all direct sunlight viewable today,” Lupo says. “I don’t know any one that’s not. A lot of them use the sun for the backlighting now.”

Many units are available with a built-in sounder module. Being able to use the tender to scout holding bottom in an unfamiliar cove or sort out the position of a poorly marked or shifting channel lets intrepid cruisers make the most of their on-the-water explorations. Making sure you’re getting good data without compromising the utility of the tender is no small consideration.

Some boats can have a shoot-through-hull transducer installed, provided the bottom is solid fiberglass and there’s an access point where the transducer can be placed. This is ideal since it will be protected from the chocks and rollers that invariably play a role in shipping a tender. Otherwise many tenders opt for a transom-mount transducer. The advantage here is that transom mount tenders have a bracket that can be folded to flip the transducer element up—and hopefully out of the way—at the first sign of danger, such as being dragged down the beach when the tide has left the dinghy high and dry. Still another advantage, a transom setup is easy to repair should something happen to it.

Optional Extras

As tenders grow in size and complexity the additional equipment they carry knows virtually no limit. However, the idea of including additional electronic systems is appealing for the added functionality.

The diesel jet drive RIBs from Williams Jet Tender use Raymarine systems for full-on engine monitoring ( “Recently we have begun equipping Sportjet and Dieseljet tenders with Raymarine systems,” says Chris Rimmer, president of Williams Performance Tenders USA ( “We fit the Raymarine i70 because it’s compatible with the latest-generation Yanmar diesels. We also offer a-Series plotters, Ray 60 VHFs, as well as AIS.” Williams Turbojet tenders get Garmin electronics ( Keeping an eye on the engines means you’ll know when something needs a closer look.

Some folks live for their tunes, and a stereo, such as those engineered by Fusion Entertainment specific to the marine environment may be a great addition, including a smartphone dock that seals the user’s phone away from the elements while allowing access to the music on it. Simrad, Lowrance, and Fusion also make black-box stereos that put functionality on an MFD screen from all major manufacturers, another solution when helm space is at a premium.

Another additional piece of equipment that you might want to carry aboard is a FLIR Ocean Scout TK handheld thermal imager (, a big step to bring this marinized technology out with an MSRP of $599. Consider the safety aspects of having the proper equipment to help locate a person in the water quickly.

Regardless of the size of kit you want to carry on your tender, you’ll want to keep track of its power usage and whether spare batteries should be kept handy, or a house battery needs to be sized up to handle the power draw. Some installers recommend using a photovoltaic panel to keep the batteries topped up. And with the right gear, you won’t have to try to remember to leave someone behind on the big boat.

This article originally appeared in the April 2016 issue of Power & Motoryacht magazine.