Detachable outriggers will be required to stabilize our hot tub and keep it from tipping over in the water. They’ll also include cup-holders and built-in storage compartments for an ice bucket and a marine battery.

After building the exterior box frame for them, we came up with the ingenious idea of placing using plastic cups and a plastic container to serve as a mold of sorts, pouring two-part polyurethane expanding marine foam around them in the hopes that the foam will fill in the space around them while leaving perfectly-sized voids suitable for the cup-holders and storage compartments.

What we didn’t account for how much the foam expanded overnight: it crushed our plastic cups and warped our plastic container forcing us to cut the shapes out anyways. Unfortunately with foam, it’s a lot of trial and error.