Nice boa! I just love them. They eat like champs and are so fun to handle.
I have one word of advice, though. if he is soaking a lot, he may have mites or ticks. When I got my boa, he was soaking a lot. Upon further inspection, there were tiny, but visible-to-the-eyel mites floating in the water. Hopefully, though, your boa just likes soaking and there's nothing to worry about.