Engine Compression Help!

[kateye57]

what is considered to be good engine compression when shopping for a used boat with about 500 hours?

[polkaking27]

anything over 100 is considered a good compression as long as all cylinders are within about 10-15 psi of each other. so if you had compression of 110, 150,155,146,142,148 that would be bad because 1 cylinder is more than 10% off