Since that page doesn't have a play button for the Splash song it lists I can't tell what rendition it actually it, but it's almost certainly mislabeled.
This is Splash as featured in Marathon 1. I can't tell by ear which QTMI is playing the MIDI in this YouTube recording but apparently it's 2.0 because...
This is Splash as featured in Marathon 1 which a comment identifies as having the (incorrect) QTMI 2.5.
This is the canonical version of Splash as featured on the Marathon 1 CD that somebody apparently uploaded to YouTube against Alex's wishes
This is the version of Splash by Craig Hardgrove featured in Eternal.
This is a version that Matecha apparently made at some point.
This is someone else's version I just now found on YouTube.
Never heard of a version by Power of Seven but you're probably thinking of one of those above.