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2018-04-15

Droning on about drones

Vista enhanced: The view from a drone. Photo still (c) http://www.captaincurran.com/2014/11/how-to-fly-drone-from-your-boat-1.html
Small, reasonably priced, remotely controlled (by either smartphones or dedicated console) camera drones are not just for annoying people and pets in public parks with their high-pitching whining. For the cruiser, they offer some practical advantages...if you can keep them free of the rigging. Not to mention your delicate flesh.

The advantages of the drone aboard the cruiser go quite a bit beyond boat selfies and bringing a bit of local colour to one's passagemaking blog. Some of them can be flown in fairly stiff breezes (although retrieving them can be tricky), and a range of several miles, using drones as "eyes in the sky" could reveal approaching weather or marine traffic, or even, when used as a "virtual crow's nest", reveal potential obstacles, such as wrecks or coral heads, that could ruin an otherwise beautiful lagoon visit.

It's important to note, however, that most drones are limited by their software as to the altitudes to which they can ascend; this is for practical reasons, such as the safety of aircraft, which also restricts drone operators as to where they may be flown at all. At sea, however, and away from land-based air traffic, there are fewer restrictions beyond battery runtime. Even so, a height of 100 metres is significant from sea level and is five to six times higher (and therefore gives a great "height of eye" distance to the observable horizon under fine conditions) than even the view from the top of the typical mast. For instance, our approximately 15 metre tall mast on Alchemy allows me to see an object of sufficient size on the horizon at 13.8 kilometres away; 100 metres of altitude on a drone would allow nearly 36 kilometres. And that's for relatively low objects; a ship of sufficient height could be seen even farther away, and a squall line thousands of metres tall would be obvious even further away and long before those on deck perceived the dark line of it approaching. This interests me, and not just because I've yet to install a lazyjack setup.
Mast steps galore: The smaller one's feet, the smaller the step can be; but the shorter the crew, the closer they'll have to be. Photo (c) Don Street/Cruising World.

In the past, the only way to get this sort of vantage point was by sending up the sharpest-eyed crew on mast steps, which was more convenient than just a bosun's chair alone and arguably safer as the last ones at the mast top gave the crew a place to more or less stand while repairing light fixtures or other mast-top fixtures, or examining standing rigging or freeing a snagged or damaged furler part.

The most esthetically pleasing mast step, as well as the least-likely to snag sails or lines, is the folding type.
But mast steps add weight and complexity aloft and can be expensive to purchase (depending on how many you require, which is a function of leg length and mast height) and laborious to install. (In the link provided, the fasteners are rivnuts, which I use with the solar panels; rivets or tapped machine screws are also possible choices). There's also a concern present in my mind of putting so many holes in one's mast and whether that has a compromising effect on its strength.

I would not hesitate to place a pair of mast steps near the mast top (particularly ones that are simple to fabricate, would be unlikely to snag anything, and would fit my huge feet), because I can see the point of that when combined with that bosun's chair. But installing mast steps all the way up just to get a better view? Perhaps the drone as nav aid makes more sense. Much as AIS complements RADAR, it strikes me that a live feed from a drone ahead of the boat would complement the forward-looking sonar we are already using

I think that the most productive use of drones at sea, apart from littering one's blog with stunning aerial shots, would be in noontime approaches to gaps in reef walls to confirm the least-tricky turns and the presence of uncharted coral heads. It was about two years ago that I realized drones were becoming cheaper than a full set of mast steps, and, because they can look directly down from well in front of the bow, are better for spotting keel-threatening hazards. I can easily see when an overlay of GPS co-ordinates and virtual AIS markers could use live drone inputs sent directly to the plotter so the tech-savvy could steer safely in undercharted areas by "live charting". Perhaps someone is already doing this: it seems like the future.

Logically, the most compact drones with the longest ranges and flight durations would be preferable for onboard use, but compact and long flight times don't always appear in the same models. Another consideration is the danger of losing something that costs one thousand dollars or greater into the salty sea; few current drones are capable of water landings (or take-offs or easy COB-style retrieval) and that's also going to restrict their use to fair weather and plenty of on-land practice prior to on-deck snatches) and the ones listed here seem too toy-like (or expensive) to take to sea, or to crash into it.
This is indeed wee. Photo (c) Steve Mitchell/Sailbits.com

Ocean cruising is a niche activity, and drone use during it is a niche of a niche, so word gets out quickly as to what works and what doesn't. A popular drone maker, and not just at sea, is DJI; their Mavic Pro and Phantom models seem to have quite a few fans, and I like how compactly the Mavic model can fold down to the size of a shoe for stowage. In January, I attended a rigging seminar with Andy Schell and Mia Karlsson of 59 North.com and the good ship Isbjörn. Andy and Mia run a popular charter business aboard their Swan 48 and they travel to some seldom-frequented latitudes worthy of shooting in high-definition with their DJI Phantom drone.
The DJI Phantom 4 drone: It's the handles you want to reach for.


After the seminar, which featured quite a lot of cinema-grade footage of Isbjörn underway, I asked Mia about the Phantom's performance parameters. She suggested the "big loops" of the Phantom model seemed superior in terms of safe retrieval; its maneuverability, being a larger drone, made it easier to control. I was surprised to learn that the drone could be flown easily at 15 knots apparent wind speed, although Mia suggested this was a big power drain and made retrieval increasingly difficult. 

There's plenty to consider before we ante up for a drone, but I think before we leave, I will have it sorted out for consideration as another useful tool in the navigational armoury. After all, if it's good enough for Paul and Sheryl Shard, who am I to disagree?

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