The object ws sighted from the cockpit of a Choey Lee sloop, docked by a condo on a causwat between Miami & Miami Beach. It first appeared rising from the glow of city lights west of us. At first I thought it was an airplne leaving MIA, but quickly thought otherwise as there was an orangish pulsating glow around it. It's speed seemed incredible. As it neared us it appeared to be disk like with green & red lights alternately around its edge. When it was about overhead it ssuddenly shot straight up & then headed north as a circular glow that very quickly dissapeared. The other three observers were my wife, an author, who owned the boat & his wife. The next day my wife & my friend independantly phoned the Miami Herald to ask if NASA had sent anything into space, & if anyone had reported anything unusual in the skies. The answers were negative. We kept quiet less our friends & business associates miht think us looney.