The meaning of 'baptidzo'

Those seeking to translate the Greek word baptizw, especially Baptists, often look to the literal meaning of its root word, baptw, which is 'to dip'. But in I Corinthians 10:2, ebaptisanto is used in a metaphorical sense that seems to give a hint at another literal meaning: the Israelites are said to have been baptized "in the cloud and in the sea." Now, translating this could be a bit difficult if one just used the word 'immersed', as the relationship of the Israelites to the sea (as contrasted to that of their Egyptian pursuers) could hardly be described as 'immersion.'

We know that this is a metaphorical usage because of the previous verse, which states that they were "under the cloud" and "passed through the sea"--the literal situation. That 'baptize' was used to describe both these situations shows that its meaning cannot be strictly limited to the going-down-in-and-coming-back-out of immersion. Thus a lifeboat in heavy seas could be described as being 'baptized' by a huge wave*; and a person receiving a few gallons of water dumped on his head while kneeling in water could described as 'baptized' in the water. The essential element in both seems to be that the one must totally overwhelm the other. The case of the Israelites seems to have been a composite one, as the sea overwhelmed them only on the sides, and the cloud overhead. Perhaps this is a hint at a dual meaning of the baptism ceremony: burial with Christ as descending into the water, and infilling with the Holy Spirit as having a container of the same water simultaneously poured over one's head (which in fact seems to have been the practice of the church in the early centuries).

This reminds me of a rather humorous scene I witnessed (via video) at a mass baptism in Romania. It took all day to baptize the several hundred new Rom believers, so they were hurrying them through as fast as they could without cutting out any of the ceremony. One woman was dipped backwards into the river, but not quite far enough, leaving her bangs and forehead dry as she came back up. No problem; the baptizer quickly slung water onto the dry spot with his free hand, thus rendering her fully baptized (even though not fully immersed).

If I had to suggest a literal translation of baptizw, I would probably suggest something along the lines of "overwhelm." But inasmuch as the word baptism has long claimed the distinctive meaning in the English language as a ritual involving water which is administered to a convert to Christianity, I would not suggest trying to replace it, so much as explaining it--as I have in fact done here.

*I heard a mariner speak of being submerged in just such a circumstance, using the phrase, "two more like that one and we all qualify as submariners," or words to that effect--thus erasing the typical distinction between a submarine going down into the water and a surface craft having the water come down over it.

UPDATE NOVEMBER 2013:
The Meaning of βαπτίζειν in Greek, Jewish, and Patristic Literature is a forthcoming journal article that addresses this question in scholarly detail. An earlier version of it is already available here.
He proposes the translation "put under water" for all but the clearly figurative uses of the word in Scripture.