It's been a long time since I've looked at this game, but I'm sure my
intention was to limit each player to at most two dolphins per file,
similar to the restriction on swallows in tori shogi. Thus, bishop-moving
dolphins should only be allowed to move to files containing 0 or 1
friendly dolphins.
To clarify another issue I see posted: In my original rules draft, I
wrote: 'On capturing the opposing Porpoise, a player adds an Orca (Killer
Whale) into his reserve, and the Porpoise is permanently removed from
play.' So an Orca always remains an Orca, and can be captured and then
dropped as an Orca as well. It's possible for one player to have both
Orcas.
By the way, around the same time as I designed this game, I also created a
really complicated 11x11 Whale Shogi ('Great Whale Shogi'?), inspired by
Wa Shogi. Each of the 28 pieces per side is different and has a different
promotion; and even the pawns are unique calves that promote to the type
of whale found in their file. Anyone intereted in rules can write me.--RWS