Frazil ice is a collection of loose, randomly oriented flakes of ice in water. Frazil resembles slush and has the appearance of being slightly oily when seen on the surface of water. 
In a recent posting, it was noted that frazil can consolidate to produce skim ice and subsequently border ice. Carlo commented on the picture of skim ice (a portion shown to the right) that,
The ice crystals in the … photo show a conspicuous preferred orientation with long elements left-right in the image. This indicates that forces at the water’s surface were not equal in all directions. When I mentioned this to Alistair, he suggested that there may have been a very gentle swell impinging on the shore. This would tend to orient the free-floating frazil with their long dimension parallel to the shore, accounting for the observed directed pattern. Neat!
Yesterday, I saw it happening. Frazil along the shore was becoming oriented by waves.
First, an overview. Waves with whitecaps (left) are washing into a bay. There is ice along the shore where the water has washed up from earlier waves and frozen. The frazil is in the centre.
A closer view shows the frazil to be grains of ice floating on the water and moving up and down with the waves.
This view, elsewhere along the shore, looks directly into the approaching frazil-carpeted waves. The frazil is becoming oriented in a manner consistent with Carlo’s suggestion.