180 wont have hurt your boat, I am not a mechanic but I have spoken with a journeyman about temp in a boat. My truck runs at 100 degrees Celsius which converts to 212 degrees fahrenheit.I wouldnt bother with the compression check. Unless you had it pegged at 240 in which case I would do it but I thought the same thing a few years ago and this is what i was told so save you money and dont worry about it.