Webster's Revised Unabridged Dictionary · 1913

Dive

Dive , intransitive verb

[Old English diven, duven, Anglo-Saxon d{not transcribed}fan to sink, transitive verb, from d{not transcribed}fan, v. i.; akin to Icelandic d{not transcribed}fa, German taufen, English dip, deep, and perh. to dove, n. Compare 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
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. Burroughs

The colloquial form dove is common in the United States as an imperfect tense form.

2.
Figuratively: To plunge or to go deeply into any subject, question, business, etc.; to penetrate; to explore. — South

Dive , transitive verb

1.
To plunge (a person or thing) into water; to dip; to duck. [Obsolete] — Hooker
2.
To explore by diving; to plunge into. [Rare]
The Curtii bravely dived the gulf of fame. — Denham
He dives the hollow, climbs the steeps. — Emerson

Dive , noun

1.
A plunge headforemost into water, the act of one who dives, literally or figuratively.
2.
A place of low resort. [Slang]
The music halls and dives in the lower part of the city. — J. Hawthorne