Sailing (Directly) Into The Wind

Humans have been sailing various seas and oceans for thousands of years, and using boats for potentially even longer than that. But as a species we wouldn’t have made it very far if it was only possible to sail in the same direction the wind is blowing. There are a number of methods for sailing upwind, but generally only up to a certain angle. [rctestflight] wondered if there was some way of sailing straight upwind instead and built this rotary sail craft to test the idea.

Normally a boat sailing upwind will sail approximately 45° into it, then “tack” 90° across the wind until they’re at another 45° angle from the wind, this time facing the opposite direction. This back-and-forth nature is not the most efficient path, so this vessel uses a few propellers to bypass the traditional sail. The first iteration, built on a sleek catamaran hull, uses a large propeller to catch the wind’s energy, then transfers it mechanically through a set of shafts to an underwater prop.

It took a few tries to get the size and pitch of both propellers narrowed down to where the boat would move forward into the wind, but move it does. A second major iteration of the build uses a single shaft with no gears, with the trade-off that neither propeller is facing an ideal direction, but this has the added benefit of the boat naturally pointing itself upwind.

While none of the designs are speed demons, the concept is sound enough. It’s just that, in most cases, performing multiple tacks to get upwind is acceptable compared to the extreme efficiency losses and drag from propeller-driven sailing crafts like these. A more effective way of propelling a boat upwind, at least using modern technology, might be to trade sails for solar panels.

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Polynesian Wayfinding Traditions Let Humans Roam The Pacific Ocean

Polynesian cultures have a remarkable navigational tradition. It stands as a testament to human ingenuity and an intimate understanding of nature. Where Western cultures developed maps and tools to plot courses around the world, the Polynesian tradition is more about using human senses and pattern-finding skills to figure out where one is, and where one might be going.

Today, we’ll delve into the unique techniques of Polynesian navigation, exploring how keen observation of the natural world enabled pioneers to roam far and wide across the breadth of the Pacific.

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Learn Sailing Mechanics Without Leaving Dry Land

The ancient art of sailing can be very intimidating for the uninitiated given the shifty nature of wind. To help understand the interaction of wind direction and board orientation, [KifS] designed a hands-on sailing demonstrator that lets students grasp the basics before setting foot on a real sailboat.

The demonstrator uses a potentiometer as a tiller to control a model sailboat’s angle, while another stepper motor adjusts the position of a fan to simulate changing wind directions. With an Arduino Uno controlling everything, this setup affords students the opportunity to learn about sail positioning and adjusting to shifting winds in an interactive way, without the pressures and variables of being on the water.

[KifS]’s creation isn’t just about static demonstrations. It features four modes that progressively challenge learners—from simply getting a feel for the tiller, to adjusting sails with dynamic wind changes, even adding a game element that introduces random wind movements demanding quick adjustments. [KifS] mentions there are potentials aspects that can be refined, like more realistic sail response and usability, but it already achieved the main project goals.

There are a myriad of potential ways to add new tech to the ancient art of sailing. We’ve seen a DIY autopilot system, full sensor arrays, and an open source chart plotter. It’s even been proven you can have a wind powered land vehicle that travels faster than the wind.

$10 000 Physics Wager Settles The Debate On Sailing Downwind Faster Than The Wind

By now, many of you have seen the video of [Rick Cavallaro]’s Blackbird, the controversial wind-powered land vehicle that can outrun the wind. The video has led to a high-profile $10 000 wager between [Derek Muller] aka [Veritasium] and [Alex Kusenko], a professor of physics from UCLA. [Veritasium] won the wager with the help of a scale model built by [Xyla Foxlin], and you need to watch the videos after the break for some excellent lessons in physics, engineering, and civilized debate.

After seeing [Veritasium]’s video on Blackbird, [Professor Kusenko] contacted him and said the performance claims and explanation were incorrect. After a bit of debate [Veritasium] proposed a wager on the matter, which [Professor Kusenko] accepted, and it was made official with a written agreement witnessed by [Neil deGrasse Tyson], [Bill Nye], and [Sean Carrol]. From the start, it was agreed that the entire debate would be made public.

[Professor Kusenko] made a very thorough and convincing argument, backed by calculations, against the claims in the video. He claimed the observations were due to a combination of gusty winds, a vertical wind gradient. He was convinced and that the vehicle would not be able to maintain a speed higher than the wind, directly downwind. By [Veritasium]’s own admittance, his original video could have contained more details and proof of performance claims of the Blackbird vehicle. He added these to the latest video and included two model demonstrations. The model that brought the concept home for us is at 13:46 in the video, and substitutes the propeller for a large wheel being driven by a piece of lumber being bushed across it. The second model, built by [Xyla Foxlin] was designed to demonstrate the concept on a treadmill. The 4th version of [Xyla]’s model was the first to be successful after she found out from [Rick Cavallaro] that the key design detail is the Vehicle Speed Ratio, which must be 0.7 or less. It is the pitch of the propeller divided by the circumference of the driven wheel, assuming a 1:1 gear ratio. All the 3D files and details are available if you want to build your own downwind cart. Continue reading “$10 000 Physics Wager Settles The Debate On Sailing Downwind Faster Than The Wind”

Sailing Faster Than The Wind Itself

If you search the outer reaches of the internet you will find all sorts of web sites and videos purporting to answer to free energy in the form of perpetual motion machines and other fantastical structures that bend the laws of physics to breaking point. We’d love them to be true but we have [Émilie du Châtelet] and her law of conservation of energy to thank for dashing those hopes. So when along comes a machine that appears to violate a fundamental Law of Physics, it’s reasonably met with skepticism. But the wind-powered vehicle built by [Rick Cavallaro] looks as though it might just achieve that which was previously thought impossible. It’s a machine that can move with the wind at a speed faster than the wind itself.

A fundamental law of sailing boats is that when they are sailing with the wind, i.e. in the same direction as the wind, they can’t sail faster than the wind itself. Sailing boats can go faster than the wind powering them by sailing across it at an angle to create lift from their sails, but this effect doesn’t work as the angle tends towards that of the wind.

The vehicle in the video below the break is a sleek and lightweight machine with a large propeller above it, which we are told is not the windmill power source we might imagine it to be. Instead it mimics the effect of a pair of sailing boats sailing across the wind in a spiral around a long cylinder, and thus becomes in effect a fan when turned by the motoin in the craft’s wheels. The drive comes from the wind working on the craft itself, and thus as can be seen from the motion of a streamer on its front, it can overtake the wind. It seems too good to be true at first sight but the explanation holds water. Now we want a ride too!

For fairly obvious reasons, the fantastical world of pseudo-physics isn’t our bag here at Hackaday. But if something might hold promise we’ll at least give it a look. Not all such things we cover turn out to change those Laws of Physics, though.

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An Open Source Shipboard Computer System

We’re not sure how many of you out there own a boat large enough to get its own integrated computer network, but it doesn’t really matter. Even if you can’t use this project personally, it’s impossible not to be impressed with the work [mgrouch] has put into the “Bareboat Necessities” project. From the construction of the hardware to the phenomenal documentation, there’s plenty that even landlubbers can learn from this project.

In its fully realized form, the onboard computer system includes several components that work together to provide a wealth of valuable information to the operator.

Inside the Boat Computer module

What [mgrouch] calls the “Boat Computer” contains a Raspberry Pi 4, a dAISy AIS receiver, an RTL-SDR, a GPS receiver, serial adapters, and the myriad of wires required to get them all talking to each other inside a weatherproof enclosure. As you might expect, this involves running all the connections through watertight panel mounts.

Combined with a suite of open source software tools, the “Boat Computer” is capable of interfacing with NMEA sensors and hardware, receive weather information directly from NOAA satellites, track ships, and of course plot your current position on a digital chart. The computer itself is designed to stay safely below deck, while the operator interacts with it through an Argonaut M7 waterproofed HDMI touch screen located in the cockpit.

For some people, that might be enough. But for those who want to do big, [mgrouch] further details the “Boat Gateway” device. This unit contains an LTE-equipped WiFi router running OpenWrt and all the external antennas required to turn the boat into a floating hotspot. Of course it also has RJ45 jacks to connect up to the other components of the onboard system, and it even includes an M5Stack Core with LAN module so it can display a select subset of sensor readings and navigational data.

If you’d like to do something similar on a slightly smaller scale, we’ve seen sailing computers that pushed all the data to a wearable display or even a repurposed eReader.

Traffic Updates On The Seven Seas: Open Source Chart Plotter Using A Raspberry Pi

As the Raspberry Pi in its various forms continues to flow into the wild by the thousands, it’s interesting to see its user base expand outside beyond the hacker communities. One group of people who’ve also started taking a liking to it is sailing enthusiasts. [James Conger] is one such sailor, and he built his own AIS enabled chart plotter for a fraction of the price of comparable commercial units.

AIS transponders in the Mediterranean. VesselFinder

Automatic Identification System (AIS) is a GPS tracking system that uses transponders to transmit a ship’s position data to other ships or receiver stations in an area. This is used for collision avoidance and by authorities (and hobbyists) to keep an eye on shipping traffic, and allow for stricken vessels to be found easily. [James]’ DIY chart plotter overlays the received AIS data over marine charts on a nice big display. A Raspberry Pi 3B+, AIS Receiver Hat, USB GPS dongle and a makes up the core of the system. The entire setup cost about $350. The Pi runs OpenCPN, an open source chart plotter and navigation software package that [John] says is rivals most commercial software. As most Pi users will know the SD card is often a weak link, so it’s probably worth having a backup SD card with all the software already installed just in case it fails during a voyage.

We’ve seen AIS receiver stations built using the RTL-SDR, as well as a number of projects around the AIS equivalent in aviation, ADS-B. Check out [John]’s video after the break. Continue reading “Traffic Updates On The Seven Seas: Open Source Chart Plotter Using A Raspberry Pi”