a translucent sphere the size of a helicopter crusing over the river at approx. 40 miles an hourWhile in bed looking out the window from the lower level of the boat I saw a sphere approximately the size of a helicopter cruise by at about 40 miles an hour. It appeared to be above the shoreline in front of the dark shadowed mountains but not above the mountains in the sky. I was gazing out the window and it suddenly dawned on me "what was that". There were no lights on it which I felt was odd but it appeared to be sort of luminesque and sort of a brownish coppery color and translucent. It moved in a very straight line over the water not wavering or turning just "crusing down the river". The time was approx 2:30 am and there were no lights on the water, very quiet except for the boat engine. The sky was clear and somewhat moonlit. I asked others if they saw it the next day but none had.