spawn guardian in ocean and deep ocean

Hello, i have a question about mythic mobs, i see the randomspawn feature in which we can choose the biome where the mob spawn

http://mythicmobs.net/manual/doku.php/databases/spawners/randomspawners

basically, i just want to know if its possible to spawn guardian and elder guardian in ocean and deep ocean, but not only near ocean monument, i want them everywhere with a ratio

mobs only pop on ground or they can pop in water too ?

thanks