The rowfoil is a vessel that can fly on hydrofoils just above the water. The drive is not by means of a propeller but via one of the foils that moves through the water like a whale’s tail on the rhythm of the rowing stroke and at the same time provides upward force so that the vessel can ‘fly’ just above the water.
The back and forth rowing bike movement is transferred to the driving hydrofoil by means of Dyneema®  lines. The pitch of the propelling foil is under control by the water surface touching lever in front of the vessel thereby controlling flight altitude.

This is the missing link in the many applications of hydrofoils and pumping surfboards on foils.
The problem with pumping foil surfboards is that you also pump your own weight up every time, which is extremely tiring. Just like with the rowing bike, the movement is rotated 90 degrees and as soon as you are in the flying phase you click on the weight compensation by overstretching. This is achieved by means of (gas) springs (or elastics) that are connected via a Snek / fusee. The fusee levels out the increasing spring tension.

Many embodiments are possible.
The obvious option is the version with 1 or 2 floaters with which you can also start from the water.
The first prototypes used 2 floaters between which the rowfoil construction was placed.

If you want to go for absolute speed (records) you can make an aerodynamic covering / fairing around the rowfoil and rower, which is also the boat / floater for the water start. This fairing will look like a flying boat. The pitch control can be controlled electronically here by an altimeter at the front and a small servo motor for pitch control. This small amount of energy can be generated using solar cells on the bodywork or a dynamo on the rowing movement.
The foils for an easy start will look very different from the foils of the record rowfoil flying boat.  Just like in foil and kite surfing, foils will be designed and made for different purposes.

Another possibility is the use of a launch installation.
If you launch the rowfoil at an initial speed, you do not need floats, as the rowfoil flies due to the hydrodynamic upward force of the foils.
You get a Star Wars-like appearance on and above the water.

You can place a mobile launch installation on, for example, a trailer, but you could also place various launch installations at the rowing lanes and marinas where your rowfoils are launched at speed into the water via a slide. At the back of the “runway” you land on a slide where you can hoist or pull the rowfoil upwards. At the top you are ready for the next trip/flight.
The rowing clubs can construct additional scaffolding for this purpose, see image of a design for the Willem Alexander rowing track in Rotterdam, the Netherlands.

For several decades I have been thinking about the idea of ​​a plunging wing aircraft and vessel. The plunging wing aircraft has now been realized, see https://rowingbike.com/posts/vliegen-als-een-vogel-het-is-todd-reichert-gelukt/
I am happy that I was able to work on the snowbird as a partner and sponsor.
For several years now I have been spending my scarce free time on the plunging wing vessel: the rowfoil.
The development process of this new sport is time and money consuming.  After an initial reasonably working prototype ( I am not that far yet), further development really begins! My time and financial resources are limited, so I hope that the Robbert Das competition will mainly generate publicity around the rowfoil and also hope to attract other designers and companies in this direction.