How important are they?
How important are they? The guy I bought the boat from told me they were bad, but that he has run the boat the last 2 seasons without them. Are they really a necessity to replace?
Other than a curiosity I can't think of anything as useless as a trim guage. Every time you take your boat out its a fair bet the water conditions are different, your boats load is different, the load is distrubuted differently, etc. Heck, even running one direction on the water and then coming back will be different and all of these differences means you trim out a bit differently and have to do it to fit conditions, not put a needle at a spot on a guage.