You do NOT need a Canal Agent - it's very easy, and cheaper, to do the process yourself. You will find the Panama Canal
Authorities to be friendly, courteous, and very professional. For our transit, this year, we used one of the taxi's for our tires and lines and were very pleased, we used him again to return our line handlers (cruiser friends) back to Panama
City. Ask the local cruisers (VHF morning net) for names of best taxi drivers and their services, and/or check out the Yahoo Group Southbound in the Panama file for LOTS of info how to transit the canal. It's about $80 for a return taxi from Shelter Bay Marina, this is usually set up and paid by the Captain
. Enjoy the trip!