Land, air, sea: three worlds in one catalogue

Splitting a vehicle catalogue into land, air and sea looks like an easy decision at first. The difficulty is not in the split; it starts when you try to keep all three worlds in one table. A car's body type and an airliner's body type go by the same word without meaning the same thing.

The land side is the most crowded and the most familiar. Passenger cars, heavy commercial vehicles, motorcycles and construction machines all meet on the same ground while doing entirely different jobs. The distance between Volvo FH and Vespa Primavera says everything about how wide the land category is.

On the air side there is less branching but sharper separation. Civil aviation, rotorcraft, unmanned aircraft and engineless flight do not blend into each other; a Schleicher ASK 21 and an Airbus A350 live in the same tree without sharing a single sub-branch.

The sea side stretches furthest from end to end. Giant merchant ships and single-rider watercraft sit under one main category. The gap between Vale Valemax and Yamaha WaveRunner is a good illustration of how little a category name says on its own.

Keeping three worlds in a shared schema costs each of them some of its own detail. This catalogue makes that trade knowingly: the shared fields are filled for every vehicle, and domain-specific detail is left to the body text. How to tell those two apart on a vehicle page is covered in What to look for on a vehicle page.