Ahoy

(used as a call to hail another ship, attract attention, etc.)
Historical Examples

After the piers were ran out they hooked on at the steps p. 60calling aloud, “Woodside, ahoy!”
Recollections of Old Liverpool A Nonagenarian

I shall go down to the pier, and call out to my men, ‘ahoy!’
Trapped by Malays George Manville Fenn

Captain Bricker, in charge of the squad, strode to the Snark and called loudly: “ahoy, there!”
Signal in the Dark Mildred A. Wirt

Eben Megg had only just disappeared when the faint, monotonous cry of “ahoy!”
The Lost Middy George Manville Fenn

He told Bill to hail, which was done with a truly sailor-like “ahoy!”
Radio Boys Loyalty Wayne Whipple

The immediate answer to this remark was an “ahoy, there, on board the Viking!”
The Rival Campers Afloat Ruel Perley Smith

This cap was tilted back, and as we ran alongside, a man stuck his head up over the rim and sang out, “ahoy there!”
Aircraft and Submarines Willis J. Abbot.

I threw up a light at once and heard the hail, “Spray, ahoy!”
Sailing Alone Around The World Joshua Slocum

Then the shrill whistles were heard along the line, calling “All hands” to “clear ship for action, ahoy!”
The Two Admirals J. Fenimore Cooper

She went to work to raise the wheel unaided, shouting “ahoy!”
Magnhild Dust Bjrnstjerne Bjrnson

interjection
(nautical) a hail used to call a ship or to attract attention

1751, from a + hoy, a nautical call used in hauling. The original form of the greeting seems to have been ho, the ship ahoy!