The Personal Go Fan fits into the category of “why didn’t I think of that?”

Powered by a lithium-ion battery, the PGF has a brushless motor whose armature spins on quiet ball bearings. A thumbscrew below the motor lets you vary the fan’s angle, and the on/off switch also adjusts the speed. A single charge, the maker estimates, provides about 40 hours of running time at the low setting and 3½ on high. Maybe the cleverest feature is the way the fan mounts in the cup holders found on most boats. $230. Cynwark Corp., Houston, (888) 938-6672. pgffan.com

This article originally appeared in the May 2016 issue.