Beware the Fish! by Gordon Korman, 1980.
In spite of MacDonald Hall’s prestigious reputation, it is continually plagued by money problems. The students can’t help but notice all the budget cutbacks, and now, there are rumors that the school might even have to close permanently. The last thing anyone wants is to leave MacDonald Hall. Bruno, the school’s resident idea man and master prankster, decides to spearhead a movement to raise money and publicity for MacDonald Hall so they can save the school!
Bruno, his best friend Boots, and their other fellow students try everything they can think of to spread the word about what a great place MacDonald Hall is so that enrollment will go up and the school can earn enough money to stay open. They enlist the help of the girls at the nearby finishing school to help them break a world record. The school’s science whiz, Elmer, shows the boys some of his inventions in the hope that one of them will make the school famous.
Unfortunately, as usual, nothing turns out as planned. World records are extremely difficult to break, and Elmer’s inventions backfire. One of his inventions backfires in such a way that it comes to the attention of the local police, and even the government becomes convinced that a gang of terrorists may be operating somewhere in the vicinity of MacDonald Hall.
The boys try to keep their activities secret from their headmaster, Mr. Sturgeon (or, as the boys nickname him, “The Fish”), while government agents snoop around, looking for the head of the organization that’s been issuing cryptic messages over television signals, a shadowy figure known only as “The Fish.”
This book is part of the MacDonald Hall Series (or Bruno and Boots series).