It's called the OarBoard, and is made by Whitehall Rowing and Sail in the US, using an all-plastic chassis and powder-coated aluminium riggers for resistance to salt water. It can be strapped to any paddleboard.
Cleverly, the sliding rigger keeps your bum stationary on the board to avoid the hobby-horsing that would be inevitable if the rower's body was shifting along the board all the time.
The staff at the stern is for a camera or light.
The only downside is that it costs the thick end of a grand, without the paddleboard or oars. Looks like enormous fun, though.
The designer, Harold Aune, writes in his latest newsletter:
"Just last weekend, we were out shooting video and stills with Andrea Guyon sculling an Oar Board unit on an ATX touring-style paddle board. We got some great shots and at one point a Dragon boat team paddled by and an impromptu race started. Andrea required only about half power to match speed and didn't want to see anyone overstrain themselves so she took it easy on them."Congratulations, Andrea, but dragon boats deserve no mercy. Next time, THRASH THEM.