The last few times I've used my boat the Gps speedo didn't work for ther first few minutes then all of a sudden it would just start working. Yesterday I was out and it took about an hour till it started working. The speedo head has power it just seems to have no signal. Is there a common problem with these that I should look for?

From what I understand the battery in the receiver goes dead and needs to be replaced. I have heard this from several friends that have them. Hopefully it is in a place that you can get to the back of where it is mounted.