Topsides refer to the section of a vessel's hull that is located between the waterline and the deck (or rail). It represents the upper, visible outer surface of the boat that is not submerged, and is often painted or finished for aesthetics and protection from the elements.

Key Aspects of Topsides:
Location: Specifically the vertical or sloping sides of the hull above the water, not including the deck itself.

Contrasts: Contrasts with the "bottom" (below the waterline, typically coated with anti-fouling paint) and the "deck" (horizontal top surface).

Maintenance: Often requires specific maintenance and painting to maintain appearance and durability.

Contextual Uses:
Sailing/Boating: The sides above the water.

Shipping: The upper part of the hull.

Offshore Industry: On an oil platform, "topsides" refers to the entire upper structure above the water, containing production equipment and accommodations.