[sector24]

The easiest way to get in the water is probably with undead units which are usually amphibious. Fighting into the water is quite frustrating. I remember one of my first games as EA Pangaea, I sent what I thought was a huge army of centaurs into the sea with water breathing items on my commander, only to be slaughtered by 1100 starving (and ravenously hungry) tritons.

Learning from that experience, I recommend quality over quantity. A wraith lord with a good sword and shield will really plow through the junk that the AI recruits. If you use items like the sea king's goblet to take landlubbers underwater, make sure you're taking the very best units you have, because they'll probably be heavily outnumbered.