this time I resort to.. wait for it..

OED2: view-halloo

The shout given by a huntsman on seeing a fox break cover. Also fig.

your particular variant is first attested to Baron Edward G. E. L. Bulwer-Lytton, in My Novel (1853): "The Squire.. bellowed out with all the force of lungs accustomed to give a View-hallo!" [yes, that Bulwer-Lytton.]

-joe (hello, sailor) friday