Compass before GPS
Kurt, you are on the right track. At Ease gave you good advice.Ray, I don't know where you sail, however If you have only one instrument on your boat it should be a compass.You should never go without a compass if you are going to sail in an environment that takes you out of sight of land, has fog or heavy mist on occasion or heavy rains (anything that obscures your view) or if you intend to sail in areas that you are unfamiliar with. Perhaps you always sail where you can see familiar landmarks, but then why do you need a GPS?GPS is a great invention. I have a hand held and a chart plotter. That said, several experiences indicate that you can't depend on them 100% of the time. However, I can depend on the compass as long as it is properly compensated (relatively easy to do on most fibreglass boats) and provided you keep extraneous magnetic influences away (speakers, objects that attract magnets). Anything that depends on good batteries can fail. I have chartered 2 boats that were equiped with GPSs that did not work correctly. My own hand held GPS was working as verified by taking bearings with a hand bearing compass (my own as well).I, and others, have noted that GPS readings, which are normally very accurate, may, very occassionaly, start to read several hundred feet off. I don't know why this, however if you are in hazardous unmarked, unfamiliar water you had be ready to take bearings on whatever landmarks are available. This past summer I saw my course line on my chart plotter show me going over land which was 200 to 300 feet away. My handheld said the same thing. You need to know how to navigate using a paper chart and a compass without a GPS if you are in unfamiliar territory (or you can't see familiar landmarks or navigational aids). That said, if you need to prioritize expenses, after a good compass and depth sounder I would have a GPS on board. You don't need a chart plotter. One that gives Lat and Long, together with paper charts is all that is necessary.