The NovaSail 360+ is probably the best value for the money, with a three axis flux magnet and has the option to shut off the GPS. The buttons are pretty intuitive, but the major drawbacks are that there is not a good mount for a cat with a rotating mast, you will want it on the spin, meaning that the thing is mostly inaccessible to the buttons anyway. Finally, because our world council ruling body does not have command over the English language (and therefore cannot write a clear rule ), the strictest interpretation of the GPS rule as written, as it applies to compasses, may mean that if there is a GPS functionality, even though it is turned off, may make devices such as NovaSail illegal. So, best ask the fleet for permission before you race. Frankly, this is idiotic, but they are a stubborn bunch.