cruise
To inspect (forest land) for the purpose of estimating the quantity of lumber it will yield.
cruise: walk timber to measure what you can sell
In forestry, to cruise is to walk through a stand of timber and systematically measure trees to estimate total volume and value. A cruise produces a detailed inventory of species, diameter, height, and condition across a defined area, usually expressed as board feet per acre or cubic meters per hectare. This estimate becomes the basis for harvest planning, selling timber rights, or assessing forest health.
Cruising relies on sampling rather than measuring every tree. A forester walks a grid pattern through the stand, stopping at fixed intervals to measure trees within a plot (often a quarter-acre or tenth-acre circle). Diameter is measured at breast height (4.5 feet above ground) using a diameter tape or caliper. Height is estimated with a clinometer or measured directly on smaller trees. These sample data are scaled up to project total stand volume.
A standard timber cruise uses a prism or angle gauge to determine which trees fall within the sampling plot without requiring a tape measure for every stem. The forester points the prism at each tree from the plot center; if the tree appears to lean outward past the prism's edge, it is counted. Trees are sorted by species and diameter class, and defects are noted. Modern cruises may employ GPS to map plot locations and tablets to record data in the field.
Volume tables convert diameter and height measurements into board feet or cubic volume using species-specific equations developed from felled trees. Old-growth and second-growth stands require different tables. Cruise accuracy depends on plot size, sample intensity, and the skill of the measurer. A cruise with closer plot spacing costs more but produces a tighter estimate.
The term originates from the leisurely pace required to conduct a thorough examination of timber. A cruise report is a legal document used in timber sales, estate appraisals, and sustainable harvest planning. Poor cruising leads to overpayment for stumpage or underestimation of timber value; many timber disputes turn on whether a cruise was conducted correctly.