I just came across this great independent SeaGlide build on PublicLab.org
ajawitz really did a great job with this. He even made some unique custom wings and a custom wing yoke with integrated ballast.
One choice quote from the build log:
"This is definitely one of those builds where you have very little room for improvisation as any attempt to replace even the smallest component from the original BOM with a different one has caused problems."
This is true for most of the buoyancy engine. Simple as it may look, quite a bit of engineering went into our buoyancy engine, most substitutions cause problems. That's not to say that we aren't working on improvements though...
And there is lots of room for creativity in the wing and rudder design. There's also a nice prototyping area on the PCB for adding sensors, lights, actuators, whatever you like.