I'll be building along the lines of the classic RC outrigger racing boat.
It's basically the same concept as my last year's entry, an unlimited hydroplane, but without all the lift generated by that hull. That hydroplane design doesn't seem to scale very well - with too much power and at this small size the thing kites uncontrollably. I could revise the design to make it work but I'd rather build this new one.
@Wildthing built a similar design last year but the similarity is purely coincidental. Maybe this one'll stay on the ground!