You would be surprised at how many engines have the wrong sending units installed for oil pressure gauges, sometimes showing deceivingly high oil pressure, or disappointingly low pressure. I like to know what the oil pressure really is, from cold engine to warm up -- under a load during sea trials -- and at idle Right after a sea trial. Most of the time I prefer to install my own manual gauges, unless the helm gauges are already the manual type.

Likewise with the temperature readings, there are many sections of the engine that do not have

sending units in or on them, I always use my own digital temperature reader, on all engine surfaces

Including exhaust sections, oil coolers, turbo sections / intercoolers, and heat exchangers

exhaust manifolds and riser sections are of special focus, often showing alarming temperature range variations thru out the sea trial. Riser sections are notorious engine killers, when a riser cracks (usually from internal rust and heat build up), invariably it will take the engine with it. A quick scan with the infra red digital temperature reader will save an otherwise good engine every time. All you need is a knowledgeable and detail oriented surveyor to use one (and be able to understand what he / she is reading).

True RPM is another elusive factor, I would say that about half of the engines I survey, have completely misleading helm tachometer gauge readings. Just by way of analogy, if your car speedometers were off as much as the average boats tachometers I think you would be racking up a lot of traffic violations in your daily comings and goings. I always use my own digital tachometers, or electronic scan equipment. My sea trial report will always carry true RPM readings for you to compare with the boats tachometer readings. When a cars speedometer is wrong, it can cost you in traffic tickets, when a boats tachometers are wrong and engines are either not synchronized, or are running in all the wrong ranges, the financial cost in wasted gas / diesel can border on extraordinary, to say nothing about premature wear and tear. I don't let that happen.

DC voltage readings thru out the vessel can also be an eye opener, starting out as good voltage in the engine room and ending up as low voltage at the bridge, right where all those nice electronic and very voltage sensitive. Toys live, AC voltage and frequencies can also be a problem both at the boat (especially from the gen set) and sometimes from the dock supply and connections. During the survey, I track both DC and AC voltage thru out the vessel systems especially during Gen Set operations, where governor droop lag can cause many forms of operational problems, both with voltage and frequencies.

"I ALWAYS GO THE EXTRA MILE"