It's likely that he will be drawn to water (feeling) types who remind him of his Cancer/Scorpio side. He probably identifies more strongly with his Gemini side; the water will influence what arouses his Gemini curiosity, but he may not want to fully surrender to his feelings, preferring to keep to the safety of the detached, airy way of being. He may end up with people who are more identified with water, but who also have planets in air.
But as Lin says, the whole chart needs to be taken into account.