Small rotating vortices filmed at Wailoa Boat Harbor puzzle boaters

Boaters at Wailoa Boat Harbor in Hilo reported and recorded small rotating vortices over the water that appeared suddenly with little wind on Jan. 9 and Jan. 10. The short-lived whirlwinds, commonly described as water devils, drew attention from people on shore and on vessels because they formed quickly and dissipated within moments.

The National Weather Service in Honolulu explained the phenomena as small-scale convective vortices—micro updrafts produced by localized uneven heating. According to the agency, pockets of rising air can begin to spin and briefly form small dust or water devils. These are distinct from larger wind events and are usually short-lived, but they can be striking to witness when they occur over open water near a busy harbor.

Local boaters said the vortices were visible in video and photos taken from the harbor area. The events were notable because they developed despite relatively light ambient winds, underscoring how localized heating differences between land and water can induce sudden vertical motion and rotation. For a coastal community that depends on daily boating, fishing and recreation, even nonsevere wind phenomena matter because they can create unexpected spray, gusts, or momentary instability for small craft.

From an institutional standpoint, the NWS explanation highlights the importance of local meteorological monitoring and clear communication. Micro updrafts of this type are not the product of large-scale weather systems but of small, transient thermodynamic imbalances. That distinction matters for emergency managers and harbor operators deciding when to issue advisories or alert the public. For Big Island County officials and harbor staff, such events are a reminder to keep safety messaging current for recreational users who may not expect abrupt localized features over calm water.

For residents and visitors, the practical community takeaway is straightforward: be situationally aware on the water and shore. Secure loose gear on boats, give unusual vortices a wide berth when photographing them, and report any phenomena that appear to pose a hazard to county marine services or the National Weather Service so that authorities can assess local conditions.

Our two cents? Enjoy the show but respect the water—these small vortices are mostly harmless, but they reinforce that Hilo harbor conditions can change in a blink, so keep a weather eye and tie down your gear before you head out.