I am not sure how 'marinised' the ETec is, being an American thing, they often design stuff for fresh water boating. Such as SmartTabs etc (I have had 2 positions corrode on the tabs as they aren't stainless).
Hence you see Mariner-Mercury engines here, and the equivalent is a Mercury-SaltWater in the US.
Like anything, there will be good ones and bad ones. PJ's has done a shed load of hours, and AJ had 700 hours on his Yam without it missing a beat I think.
R