![Image](https://france3-regions.francetvinfo.fr/pays-de-la-loire/sites/regions_france3/files/styles/top_big/public/assets/images/2019/11/28/temo_silhouette-4537737.jpg?itok=-12Rw5X-)
https://www.temofrance.com/en_GB/
This seems rather expensive for what it is but it looks like they have put significant thought, design effort and money into the development.
There are some exciting developments in single oar sculling in France at the moment with enthusiastic racing improving the breed. Sprint speeds in excess of 5.5 knots are being achieved with usefully sized boats. Some links:
https://universitedelagodille.org/
https://alexderoc.wixsite.com/alternav-groix/godille
![Image](https://i.ytimg.com/vi/TVYbD4uwN-U/maxresdefault.jpg)
Lastly, I agree that Paradox probably leans heavily on its rudder for lateral resistance, much like the traditional sailing boats of Venice which have an aft-mounted rig and large rudders (and have flat bottoms):
I sailed one for a day and it handled very well.