Glossary Term
HAT (Harbor Acceptance Test)
In yacht newbuild, refit, and major-system integration work, HAT means Harbor Acceptance Test. It is the structured dockside test stage used to confirm that an installed system is correctly fitted, functional, and ready to move forward before sea trials. OEM HAT procedures describe the purpose in similar terms: verify that the delivered system is correctly installed and fully functional while the vessel is still alongside.
HAT usually sits after installation and primary commissioning but before SAT, the Sea Acceptance Test. At this stage the crew, yard, integrator, and owner’s team can check interfaces, alarms, safety functions, shutdowns, controls, indications, communications, and basic operating modes without the moving variables of a sea trial. One propulsion-control HAT sequence cited in marine documentation places the harbour acceptance test between start-up commissioning and sea trial, with visual, safety, and alarm checks as core items.
For a superyacht, HAT is valuable because many faults are easier to isolate at the berth than offshore. A good HAT also produces a clean record of what was tested, what remains open, and what is deferred to dynamic trials. That makes it part of the wider tests and surveying path rather than a ceremonial milestone before delivery.