Sistah Linda you are correk! San Ignacio *is inland. You can only catch a water taxi from Belize City, Marine Terminal. You *may have to take a bus from San Ignacio to Belmopan and then transfer to a Belize City bound bus.
The water taxis leave from Marine Terminal a few times a day. I believe the latest departs about 4:30pm. It's a 40 minute one way ride to Caulker, an hour to Pedro. It is the bomb ride (bomb as in beautiful and big blue sea and sky).
blessed journey!