The Collaborative International Dictionary of English v.0.48:
Dive \Dive\, v. i. [imp. & p. p. Dived, colloq. Dove, a
relic of the AS. strong forms de['a]f, dofen; p. pr. & vb. n.
Diving.] [OE. diven, duven, AS. d?fan to sink, v. t., fr.
d?fan, v. i.; akin to Icel. d?fa, G. taufen, E. dip, deep,
and perh. to dove, n. Cf. Dip.]
1. To plunge into water head foremost; to thrust the body
under, or deeply into, water or other fluid.
It is not that pearls fetch a high price because men
have dived for them. --Whately.
Note: The colloquial form dove is common in the United States
as an imperfect tense form.
All [the walruses] dove down with a tremendous
splash. --Dr. Hayes.
When closely pressed it [the loon] dove . . . and
left the young bird sitting in the water. --J.
2. Fig.: To plunge or to go deeply into any subject,
question, business, etc.; to penetrate; to explore.