Why does Annabeth make Percy standing water in capture the flag chapter?

In "The Sea of Monsters," during the capture the flag game, Annabeth makes Percy stand in the water to use his powers as a son of Poseidon. This strategic move not only enhances his abilities, allowing him to gain strength and control over the water but also provides a tactical advantage against their opponents. By utilizing Percy's connection to water, Annabeth hopes to secure victory for their team.