A growing number of private boats also visit through mooring at the Ford Cove Marina or anchoring at Tribune Bay.

The island was found and named Isla de Lerena during the 1791 voyage of the Spanish ship Santa Saturnina, under Juan Carrasco and José María Narváez.

Broadleaf deciduous trees include bigleaf maple, red alder, black cottonwood, Pacific flowering dogwood, cascara and several species of willow.

The island's soils have developed from marine deposits of variable texture, except for the higher elevations and steeper slopes where weathered clastic sedimentary rock provides the parent material.

Most of Hornby's soils are sandy or gravelly, but some deep black loams occur in the northwestern part and many of the sands at the southern end have loam-textured topsoils.

Podzols are common and the bleached sand grains associated with their eluvial (A2, Ae or E) horizons lend a salt-and-pepper appearance to many forest trails.

[4] A species of saurodontid fish (previously considered a pterosaur) called Gwawinapterus was identified based on a fossil found on a beach on Hornby Island.