Double standard for Sail boats ?

[Electric Blue]

I saw something very interesting this weekend on the Lake. Everybody knows, or should know, that Sail boats have the right of way while under sail. While under power, sailboats have to follow the same navigation rules as power boats........but, it seems these sly sailboaters have added a new twist.
I observed at least two sail boats with there sails up, motor running, and operating as if they were under sail. They had no regard for my vessel or any other vessel as they cut across our bows, from my port side. I, as well as a few other vessels, gave way to the sail boats.......thinking they were under sail and had the right of way..... but they did not.

I was wondering if anyone had the same experience ?