The site is still online: http://www.seaglider.fr
The person behind the Seaglider site is a French guy called Stephane ROUSSON. He started working on the concept circa 2000. On this site you will find the full history of the “Sea dog” / 'Water Wing": http://www.seaglider.fr/Seaglider/Seaglider_History.html.
There you will learn that the “massless” boat concept goes back as far as 1845: http://fr.scribd.com/doc/66251685/Hagedoorn-Inventing-the-Hapa
Stephane’s work was based on the French Luc Armand’s 1990 work : “The Water Wing” : https://www.youtube.com/watch?v=1tEw_mlUh7g&feature=related. It could only go in one direction and looked pretty much like one of our Kite or Sup hydrofoils.
In 2011, another French guy called Sylvain Claudel kitesurfer and paraglider, worked with Stephane Rousson and Luc Armand to adapt the “Water Wing” concept to make it bidirectional for kitesurfers :
Sylvain Claudel’s YouTube channel is still alive: https://www.youtube.com/user/flyingcloclo/videos
In 2012, the project was carried out to a new level by the newly formed Owlone team and Damien Leroy demoed the ++ thing ++ in May 2014. If you are a kitesurfer or kitefoiler, you must watch this :