Books like Spy School at Sea by Stuart Gibbs

Twelve‐year‑old genius Artemis Fowl, a millionaire criminal mastermind, kidnaps the fairy Captain Holly Short of the LEPrecon Unit, sparking a magical adventure filled with twists, trolls and high‑tech intrigue.

A boy transfers to a CIA-run school of espionage, where he finds out the CIA and the school have more secrets than he bargained for.

Thirteen‑year‑old Ben is expelled from spy school after a shooting mishap, only to be recruited by the sinister organization SPYDER.

After a CIA assassination attempt on his life, Ben Ripley must go rogue to uncover the truth behind Erica Hale’s betrayal and track an ancient espionage conspiracy that spans from George Washington to modern spies.

Thirteen-year-old Ben Ripley has been caught in the snares of SPYDER more than once and knows well enough to be suspicious of anything that seems too good to be true—despite needing special tutoring in advanced survival techniques. So when Murray Hill finally breaks his silence with an offer to hand over the SPYDER elite, Ben knows that there must be something going on. But his hesitation doesn’t stop the assignment. The Mission: Follow Murray Hill to an undisclosed location with no one else but Erica Hale to identify SPYDER leadership. Once found, contact the CIA to sweep in and finish the job. DO NOT CONTACT SPYDER DIRECTLY. However, as Ben suspected, nothing goes as planned, and what should be an easy mission quickly turns deadly. Now, Ben and Erica will have to face rogue agents, trained killers, and even very hungry crocodiles in a race against the clock to find out what SPYDER is up to this time—and thwart their evil plans.

Kid inventor Frank Einstein must rescue his sentient robotic friends Klink and Klank from the scheming T. Edison, using real science and a dark energy drive in this humorous middle‑grade adventure.

"There are many colorful creatures to find under the sea. Look through the spy hole and use the clues to guess the creature, then turn the page to count the animals"--