FAQ

A precision 3D magnetic sensor measures the Earth’s magnetic field in all three directions. From the direction of that field, the eCompass works out which way the device, and the boat it’s mounted on, is pointing, and shows it as a big, clear heading number.

No GPS, no phone, no app needed on the water.

The eCompass only uses magnetic input, stores no data and has no functions beyond the current heading. That’s exactly the kind of compass most class rules allow, so it can be class legal in ILCA, Optimist, 49er, 49erFX, 29er and many other classes.

Class rules differ and change from time to time, so always check your class rules and the sailing instructions of your event.

Not a LiPo. 😉

It depends on the device and what it’s used for. All SEANIAC devices are charged by high-efficiency monocrystalline solar cells. Some store the energy in a supercapacitor (“supercap”). Others use storage technologies that last for far more charge cycles, keep their charge much longer in storage and handle a wider temperature range than conventional lithium batteries.

Quick test: count the gadgets in your drawer that were killed by their own battery. The earbuds that now last 20 minutes. The fitness tracker that wants charging twice a day. The action camera that switches off right before the start. The phone that “needed replacing anyway”. Congratulations, you’ve met the LiPo.

LiPos are brilliant at exactly one thing: squeezing lots of energy into a tiny, cheap package. For everything else, they’re a diva:

• Short-lived: typically a few hundred to around a thousand full cycles before they noticeably fade. Charge one every day and it’s tired within a season or two.
• Aging in the drawer: they wear out even when you don’t use them, faster when stored full and warm. As a rule of thumb, every 10 °C more roughly doubles the speed of the chemical aging. Your spare battery is getting older while you read this.
• Afraid of heat: leave one in the sun or behind a car windshield and it ages fast, puffs up like a pufferfish, and in the worst case catches fire (thermal runaway).
• Afraid of cold: they shouldn’t be charged below freezing. Good luck at the winter regatta.
• Bad travellers: lithium batteries count as dangerous goods for air freight.
• Take the gadget with them: often glued or soldered in, so when the battery dies, the whole device goes in the bin.

A boat is hot, cold, wet, salty and bouncy. A LiPo would much rather sit in an air-conditioned office.

Because they’re cheap and pack a lot of energy into a tiny space. A small LiPo cell can cost less than a dollar. That’s perfect for a bright, power-hungry screen, or for a product that only needs to last until the next model comes out.

A supercap stores much less energy, so we had to work for it: an ultra-low-power reflective display and solar cells that recharge it every time the sun comes out. In return, there’s no battery that wears out after a few seasons.

It’s solar powered, not moon powered. 😉 A full supercap keeps the eCompass running for more than 12 hours without light, enough for a long race day and a late finish. It isn’t designed for night sailing, though.

IP ratings (“Ingress Protection”, standard IEC 60529) describe how well a housing keeps out dust and water. The eCompass is rated IPX8: the X means dust wasn’t tested, the 8 means it can stay submerged deeper than 1 m.

But keeping a housing watertight for many years is notoriously hard. Seals age, temperature and air pressure changes make a housing “breathe”, and condensation always finds a way in.

So we went a different path: the housing is just for looks and to hold everything in place. The display, sensors and electronics are embedded in a thick layer of silicone, so water can’t reach them, ever. That’s also why there’s nothing inside to service, and why you shouldn’t try to open it.

Rinse it with fresh water and wipe it with a damp, soft cloth. Please don’t use solvents, detergents or abrasive cleaners.

Avoid temperatures above 60 °C, for example behind a car windshield in direct sun. When it’s not on the boat, keep it in its protective shell.

Not quite. Most people think the Earth’s magnetic field simply points from south to north. Reality has a few twists:

• Inclination: the field only runs horizontally near the equator. Further north it dives into the ground towards the pole: about 63° downwards on Lake Zurich and 69° in Kiel. Now head north in Kiel and lift the bow by just 21°: the field is now exactly perpendicular to the compass face, and a simple flat compass has nothing left to point at. (more on inclination)
• Intensity: the strength of the field varies by a factor of three, from about 22 µT off the coast of Brazil to about 67 µT near Antarctica. In Central Europe it’s around 48–50 µT. (world map of intensity)
• Declination: magnetic north isn’t the geographic North Pole. On Lake Zurich, magnetic north is about 4° east of true north. In Cape Town, it’s about 27° west. (more on declination)
  It keeps moving: the field changes slowly over time. The magnetic north pole is currently drifting towards Siberia at around 36 km per year.
  Luckily, smart scientists keep track of all this in the World Magnetic Model. It’s updated every five years; the current version, WMM2025, is valid until 2030.

Racing tip: for tactics, the absolute number matters less than the changes. A lift is a lift, whatever the declination.

Yes, anything that makes its own magnetic field. For comparison, the Earth’s field in Central Europe is about 50 µT (microtesla).

• Magnets: a fridge magnet has around 1–10 mT, that’s 20 to 200 times the Earth’s field. A coin-sized neodymium magnet reaches about 100 mT, some 2,000 times. Think magnetic phone mounts, phone speakers or magnetic clips. The good news: the field of a magnet drops very quickly with distance, so a few tens of centimetres make a huge difference.
• Iron and steel: steel shackles, tools or an outboard engine bend the field lines around them. Most marine-grade stainless steel (A4/316) is barely magnetic, but cheaper stainless can be.
• Electric currents: a cable carrying 10 A creates 20 µT at 10 cm distance, almost half the Earth’s field. Right at the conductors of a 380 kV power line, the field can exceed 100 µT, and it alternates 50 times per second.

So: mount your compass away from steel, magnets and cables, and it will happily point where it should.

Yes. A traditional compass card is balanced for the magnetic dip of its region and can tilt or stick on the other side of the world. The eCompass measures the field in all three dimensions, so dip doesn’t bother it. Take it from Lake Zurich to Sydney Harbour without changing a thing. Like every compass, it struggles only near the magnetic poles. Few regattas there.