Usually the overseas portion of these trips are co-organised by
a tour company engaged by the school, who will plan the itinerary,
accomodation, meals, etc. in the foreign country.
I think on the whole the trips are pretty educational and
interesting. Depends on what the focus is of course, if it's for a
CCA or particular subject then naturally the trip would be oriented
towards the subject.
As for how well organised it is, it depends on organisers... if
your school administration or teachers in charge are typically
quite capable and on the ball , then should be safe.
I think a big factor that affects how much a child learns from an
overseas trip is how mature & eager to learn a child is LOL. Is
he the type who can appreciate, even alittle bit, new experiences?
Naturally children are playful, but if the child is ALL about
having fun and is concerned about nothing else, then the trip is
mostly wasted on him. LOL