That's a Hobie 21 SE with a TheMightyHobie18 mast-section as the forward crossbeam and a Hobie 18 trampoline as the forward trampoline. While you may have noticed the two speaker pods on either side of the forward cross-beam (facing aft), and the two speakers in the large storage box, what you can't see are the two outdoors speakers strapped to the spreaders, facing down.
There is a very large gell-cell battery in each hull, made possible by large square hatches installed in each deck.
If you ask me, it's a lot work to build a Hobie 21 into a G-Cat!