There had been reports of Harlequins on eBird rarities and we were in the area. So . . .
We were about ready to give up when we found two adult males far outside their usual territory, in somewhat muted breeding plumage, but with typically colorful and complex coloration nevertheless. Head and neck dark blue with large white crescent in front of eye extending up to the crest. Small rounded white dot behind the eye. Oblong white patch down the side of the neck. Black crown stripe over top of the head with chestnut patches on either side. A black-bordered white collar. Lighter blue body with chestnut flanks. Never got a look at tails. Lots of waves and diving made for fleeting looks and really very poor photos.
Found at zoo, but was not part of captive animals
Note round head with straight bill; plain brown coloration with metallic greenish sheen on back.