Vaeva

Vaeva is a 1986 game by Albert Raguenes, published by Novolud.

The game is played on a 20x20 board; there is a 4x2 piece (the boat) that is placed at the center:

Each player has nine pieces

Rules:

• Players, facing each other, initially place their pieces on their first row
  
• Each player, on their turn, can either:
• move one of their pieces diagonally by one square
• jump diagonally over one or more pieces (jumped pieces must form a continuous line)
• slide the boat orthogonally by as many squares as there are friendly pieces inside the boat
• enter the boat, by sliding vertically or horizontally a piece over a line of empty squares. 
• the number of empty squares of this slide is determined by how many friendly pieces are already inside the boat (so, the first piece to enter the boat must be adjacent to it)
  
• A piece cannot enter the boat via a jump
• Wins the player that loads five pieces into the boat

The game was reviewed at Jeux et Stratègie #47:

There are some differences between Patrik Carpentier's rules and this J&S review.

• Patrik describes specific places for the game's setup:

• Patrik states the board can move orthogonally, while J&S only mentions horizontal moves
• Neither Patrik nor J&S explains what happens if the boat would move over a neighboring piece (possibly, the boat cannot move in that position)
  

J&S review also includes some comments:

• The concept of movements linked to other elements, such as the number of pieces onboard or aligned, has already been used in other Novolud games. However, in Vaeva, the very simple rules particularly highlight the depth of this principle in its tactical applications.
• Should you move cautiously or rush to board a piece as quickly as possible to take control of the platform?
• Should you be offensive or defensive, focusing on placing blocking pieces to disrupt your opponent's trajectories?
• The symmetrical progression of both players often leads to them having the same number of pieces on the platform, thus [having] the same potential to move the platform. The rule specifying that the platform cannot return to the position it previously occupied creates situations reminiscent of Zugzwang in chess, where being forced to play becomes a disadvantage.

I was unable to find online the official rules, or any other game published by Novolud.