Gibbsville Girl,
Greetings, I am the Destination Specialist on the Mariner and know a little about Belize and Sto. Tomas. Belize City is not a scenic city; the port stop is chosen for its incredible diving and snorkeling along the 2nd largest barrier reef in the world and the Maya archaeological sites. If you are not on tour, Belzie City does not hold much for the day visitor. Because of the reef ships must anchor far off-shore and tender in. Though Santo Tomas in Guatemala is growing very quickly it is still a sleepy little town - the major shipping port for what was formerly united Fruit Company. There is a new visitor's center/terminal that gives a solid roof over the heads of vendors that come down from the highlands. Guatemala is known for its weavings but the people who make them do not live on the coast - so they are imported for the ships and sell in this new "market." Other than that the stop is primarily to give guests access to the creme de la creme of the Maya world - Tikal and Copan. You need to fly to both of them; if this is not to your liking there is another site that you can drive to - Quirigua. If you are interested in tropical ecology you can also take small boats up the Rio Dulce to the town of Livingston which is home to Garifuna residents - Afro-Caribbean. Hope this helps!