What does it take to read engine hours?

[FASTFJR]

I boat is currently in indoor rack storage until spring. When they change the fluids in the fall I forgot to ask them to run the numbers. I would like to know the real hours on the motor. Is this info read by a hand held device or a larger type of computer that is hooked up to the engine?

[glen e]

it is usually read off a laptop computer that gives them a lot more data - here is a page from a Merc laptop:

[FASTFJR]

Thanks Glen, I guess thats why they want 75 bucks just to check it. I thought it might be a Scan Gauge type of deal