Mightykiter send an email to TMM Belize and ask them and their crew and barefoot charter guests to be on the lookout and call any sitings in. I don't have the email on hand but search this site and you will find the contact for TMM Belize.

Port Authority in Belize City number is 011-501-223-0714.

Immigration dept San Pedro is 011-501-206-2086

I thought I saw a boat with San Francisco written on the back last week, but I can not be certain.

By the way TMM has boats based in San Pedro and Placencia and usually has some boats in Guatemala too.