I haven't been on a college trip yet but I've had to deal with extensive domestic travel while diapered.
I don't hide my diapers. I put them out of sight, but I don't try to actively prevent them being found. I don't like them being found, but I have the right to them, especially now.
Just being on a trip, I'll usually wear Abena M3s, the same diapers I always wear - my supplier, Independence Australia, ships Australia-wide in reasonable time, so there's no real reason to change my routine.
If I'm actively travelling - in a plane, train or automobile - I'll usually upgrade to a Bambino Bellissimo or ABU Simple. Facilities are often inconvenient - such as airplane bathrooms, where you have no privacy even with the door shut, and no space. Alternatively, you may simply have no facilities at all - for example the QR Gympie North line is 180 km (110 mi) and about a 3-4hr journey but only uses EMU trains, which don't have toilets. Thicker diapers are the best choice overall.
I change in toilets, but I don't try to hide that I'm doing it.