A compass is a useful tool if you know how to use it and you don't let it become a distraction. The most important situation that I use one is ocean sailing where you may not have a stationary point of reference on a blank horizon of water. When I'm racing on closed bodies of water, I tend to use landmarks to sniff out headers and lifts but I do reference the compass to understand the bigger, more gradual, shifts that are taking place - particularly to see if they are lining up with the day's forecast.

As far as speedo's go (not the wearable kind), having a speedo on my J22 really helped shorten up the initial learning curve on how to drive and trim that boat. I'm planning to do more training with a GPS speedo on my F18 this year.

I wish I had known about the GPS rule at F18 Nationals before I got there...I probably would have brought some other devices.