The two students, Andrew O'Donnell and Max Wall, both aged 18, were on their holidays, celebrating the completion of their Leaving Certificate Exams in June. Both teenagers died in separate islands.
It has been reported that Andrew O'Donnell turned 18 on June 7. It is understood that he went missing on Friday, before his body was found in a rocky area over the weekend. Yesterday, Max Wall also died on the island.
Speaking about O'Donnell, Mr Kelleher described him as "a fantastic young man, great sportsman, fantastic footballer, played rugby in his club in his younger years and was involved and a huge supporter of the school in all facets. Academically bright and ... looking forward to his holiday, looking forward to going to college and a very, very bright future".
He also paid tribute to Max, calling him "a very bright young man, fantastic sportsman as well, passionate about his rugby and a really bright academic young man. Also, again the world at his feet and full of optimism and hope for the future".
Mr Kelleher also added that friends of the two students "got the worst possible news yesterday morning, as we all did, and we're all absolutely devastated with the news".
Calling them a "very tight knit group of young men", the principal stated that the rest of the students are "traumatised" over this tragedy.
"We are heartbroken. We have a very tight knit community and these are two fantastic young men with their lives ahead of them", Mr Kelleher said today. "Bright sporting academic men who had their whole life ahead of them and looking forward to this particular trip for months on end and the planning had been ongoing, not just in our school but in lots of other schools".
"So, I think there are hundreds and hundreds of families this morning plunged into deep, deep sadness because of what has occurred. And again we are reeling with it", Mr Kelleher continued. "It's exactly the nightmare that every parent dreads when group holidays and big groups of children go away".
"You just don't want to get the call to say your child is missing, but two of our families have had that call and we are devastated for them and our hearts are broken and our sympathy goes to them all".
Elsewhere, Tánaiste Micheál Martin paid tribute to the two students.
