I found the following excerpt from Turretin in a Baptist essay (I have not checked its accuracy, and the point for which it was presented was clearly to suggest both a particular exegesis of the baptism of the Ethiopian Eunuch and a particular historical claim as to the practice of the primitive church):
The passage of the Israelites through the Red Sea wonderfully agrees with our baptism, and represents the grace it was designed to express. For as, in baptism, when performed in the primitive manner, by immersion and emersion, descending into the water, and again going out of it, of which descent and ascent we have an example in the Eunuch, Acts 8:38, 39: yea, and what is more, as by this rite, when persons are immersed in water, they are overwhelmed, and, as it were, buried, and in a manner 'buried together with Christ;' and again, when they emerge, seem to be raised out of the grave, and are said 'to rise again with Christ;' Rom. 6:4, 5. Col. 2:12; so in the Mosaic baptism we have an immersion and an emersion; that when they - descended into the depth of the sea, this when they went out and came to the opposite shore. The former was an image of death; the latter of a resurrection. For, passing through the bottom of the sea, were they not near to death? and, escaping to the opposite shore, were they not as if revived from the dead? As in former times the persons to be baptized were immersed in the water, continued under the water, and emerged out of it; Matt. 3:16. Acts 8:38; so the old man died in them and was buried, and the new man arose." Rom. 6:4. Col. 2:12. Disp. de Bap. Nubis and Mans, § 24. Inst. Theol., tom. 3, Loc. 19, Quaes. 11, § 14.
(as taken from here)