wthalheimer

Acela and Virgin Trains are not high speed rail…

Ah I see the confusion - that overflight wave tolerance is defined by an emergency landing condition. In the extremely low probability chance that the seaglider needs to perform an emergency landing, the passengers need to be safe. That defines the 8-13ft window.

In no cases are we contouring waves in flight. We fly straight and level. Typical flight altitudes are 10-30ft above the wave peaks. The waves are well below us.

With today's tech you're spot on. As batteries advance though, we expect ranges closer to 500 miles by the end of the decade, which would indeed enable SF<>LA!

Definitely considered. Swapping means specialized training, specialized equipment (these batteries are thousands of lbs), and mass storages of batteries to be on-hand at your docks. All drive the cost higher. So far our customers have not indicated that the charge times cause them problems, and the cost savings are significant in charge vs swap.

Plus, this way seagliders can potentially utilize the same charging infrastructure as electric aircraft, boats, and busses.

Kind of a mix of both really.

Anywhere near significant boat traffic (e.g. in harbors), we'll be on our hydrofoils at speeds of 20-50 mph. So in these environments, we're just another boat (albeit a very comfortable, wave tolerant one)

We dont leave the foil to takeoff onto our wings until we leave the harbor. This doesnt need to happen on "runways" though. We'll already be at takeoff speed (~50mph) as we're leaving the harbor, so we really just jump out of the water whenever we choose to. This way we dont need to clear long stretches of water for a "runway", which has limited seaplane operations.

Absolutely agree: Seaglider operators will have to obey the rules of the road to avoid collisions just like any other boat. WIGs are actually already in the COLREGS (we're last in line for right of way, but on the list!), and our sensor systems will ensure that seaglider captains have excellent situational awareness.

That's what distinguishes seagliders from a GEV! We read the wikipedia article before setting off on this path too ;)

Seagliders are different from all GEVs (aka WIGs) and seaplanes of the past because of our hydrofoils. They lift us out of the water on stilts giving us 5ft of wave tolerance. We accelerate to takeoff speed on the foils (which lets us point into the wind even through waves) and then takeoff onto the wing and settle into ground effect.

Float -> Foil -> Fly

Yes we'll have several sensor systems onboard that augments the captains visual perception, including radar, AIS, and we're looking into computer vision systems as well.

We've been testing these sensor suites in helicopters today. Flying <50 ft off the water at speeds in excess of 100 mph, simulating the seaglider operating conditions. We have plenty of time to detect and avoid traffic even in crowded waterways at speed.

We looked into this! If you want to go regional range, you really need high speed rail (who's trying to sit on a train that goes slower than cars on the highway...)

High speed rail is prohibitively expensive. Besides the rail itself, you need to do grade separation from the ground so the rail can be flat, environmental impact studies, and in the US where private property rights are very strong, you might need to pay the land owners.

Look at the proposed price tags of the past 4 high speed rail projects in the US (none came to fruition): - California High Speed Rail: $77B - Acela High Speed Rail (NE Corridor): $150B - Texas Central: $20B - Virgin Trains Florida High Speed Rail: $4B (just Orlando to West Palm!)

I wish it was as simple as electric trains! Would save us a lot of engineering...

Previous ground effect craft absolutely were killed by their poor wave tolerance. That's where our hydrofoils come in. 5ft of wave tolerance through the harbors and in takeoff and landing. Means we can operate with very high confidence and high utilization in most markets.

We're using lithium-ion batteries (for now), so charging is like any electric car. As long as you have the power to fast charge it, you can do a full batter in ~45 mins.

That's max range (=180 miles) at 45 min charge. So let's say we're doing 90 mile missions between the islands of Hawaii, you only drain half the battery, so charge time is only ~20-25 mins - which is how long it takes passenger to unboard and board anyways!

The specific tolerance within that 8-13ft range is driven by wave period. Long period waves lets us operate more towards that 13ft end because you can contour the waves.