piperpa46 - The electronically-controlled, common rail diesel engines of today - be they marine, automotive or industrial - are pretty finicky on what they require by way of fuel.
The older diesels would run quite happily on Jet-A1 - but todays electronic models have sensors measuring fuel viscosity, and possibly even lubricity - and any fuel entering the fuel system, that is outside the strict fuel parameters set in the engine ECU by the manufacturer, would quite likely result in engine shutdown, or an ECU reset to "limp-home" mode - resulting is severe curtailment of engine RPM's and power output.
The cetane rating of Jet A1 is not measured, nor fixed, and its cetane number can vary widely - unlike diesel fuel, which is refined to a different ASTM standard (D975), and which has a defined and fairly narrow cetane rating range.
Finally - common rail fuel injection systems operate at extremely high pressures, with clearances between the moving parts of high pressure pumps and fuel injectors, running at half the clearances of the older diesel engine (which already had clearances as low as 0.0001" or 0.00254mm).
These exceptionally close tolerances and extremely high pressures require a diesel fuel with a high level of lubricity, to ensure those close-fitting fuel injection components don't seize or gall.
Jet A1 is not likely to have the same lubricity as current-specification diesel fuels, and if any particular CR diesel engine does not have fuel lubricity sensing engineered into the design, it will suffer high pressure fuel pump and injector damage, as a result of using Jet A1, instead of the specified diesel fuel.