Definitely not hydrolocked, but it could still be damaged. If ANY water got inside the combustion chambers it can cause massive problems. Water doesn't compress like air does.
Get those codes pulled and we can help from there, but at this point, it's anyones guess. The loss of power when driving can be related to a lot of things, but I'm not going to rule out engine damage. I'd really look into a compression test if I were you.