Stuart Maxwell, of Eastwood High School, Newton Mearns, said the school community was shocked and saddened by Elliot Peacock's death.
The 14-year-old died in a gorge-jumping accident while on the trip with the Eastwood District Scouts on Sunday. Italian reports said last night that, according to a post-mortem, water was found in his lungs, suggesting he died of asphyxiation, probably by drowning.
His parents, Scott and Colette, have flown to Italy and are waiting for permission to bring their son's body home. Plans are also being made to bring the rest of the Scout group and their leaders back to Glasgow.
Elliot's headteacher Mr Maxwell said: "Elliot was a lovely boy, well-liked and well-mannered.
"Everyone knew him as a nice, polite, quiet lad. He did well in all his subjects, particularly in physics, enjoyed PE and played guitar, and had a wide circle of friends.
"We were privileged to have known Elliot for the three years he was with us at Eastwood. He will be very sadly missed by everyone here and all our thoughts and prayers are with his family at this extremely sad time."