I slip into the bathtub-warm waters of Molokini Crater, situated between Kaho’olawe and Maui, and open my eyes to a riot of subaquatic Hawaiian color. Parrotfish, Moorish idols and Picasso triggerfish gallivant by, and I spot sea turtles in the enticing depths below. I pull deeply through my snorkel and aim for 5 o’clock, swimming toward the graceful terrapins until my lungs cry for oxygen. While the optics are spectacular, I can’t help but wish there were a way to peer closer at the ocean’s colorful secrets, sans gills or scuba tanks. Now there is. While humans have been dispatching remotely operated vehicles, or ROVs, beneath the brine since around the 1950s, doing so was traditionally the province of research scientists. Smaller, “low-cost” ROVs have existed since the early 1980s, but they still cost $25,000 to $45,000, so they were primarily used for commercial applications. About a decade ago, consumer interest in recreational ROVs picked up, starting with home builds and DIY kits, then progressing more recently to user-ready commercial products.