Published: Oct 15, 2010 3:36 PM EDT
Updated: Oct 15, 2010 12:36 PM EDT

SATELLITE BEACH, Fla. (AP) - Authorities are searching the waters off Florida's Space Coast for a 49-year-old dentist who hasn't been seen since leaving on a fishing trip.

Michael Alexander's empty kayak was found Thursday about 20 miles northeast of Satellite Beach. It was brought to shore by crime scene investigators for processing.

Investigators also found his blue pickup truck at a Satellite Beach park.

State and federal rescuers have been searching for Alexander by sea and land.

Authorities say the Cape Canaveral man left a note for his girlfriend on Wednesday morning saying he was going fishing. He has not been seen since.