It looks like it would be easy enough to remove it - just plug the tube and pull it up out of the way. That way you can use your GPS to settle the argument once and for all. Don't forget to post your results up on OSO for us! :D

I dont think you have to remove it, just loosen the set screw slide it up.

It is very easy to remove the tube. I just have to get in the water to do it!

If you prove it makes a difference, I will be removing the pick up for my live bait tank. I don't use the tank and it's pick up is about 4 times the size of any pitot tube pick up!

RR

I had one similar to that on my 24 Superboat. No speed difference. I got tired of constantly fixing or replacing it so I went to a GPS speedo. It got bent all the time from chit in the water hitting it.

If you already have the GPS, why not switch to a GPS speedo?

I also saw no differance in speed with or w/o it.

Wile proving to the keyboard reacers and "skeg guard will loose you speed" I tested in real life on my boat. With and w/o my pick up, speeds were the same. With and w/o skeg guard, speeds were the same. But I only play in the mid 50's MPH (55-57 depending on load) , so maybe at 80+ mph, but it made no differance in my boat.

OK, sounds like it's not hurting my speed. Thanks for the info. I don't want to replace it because I already have the giant Livorsi liquid filled speedo that works fine and I have two gps's on board now for true speed readings. Can a dash mount gps speedo be piggybacked to my chartplotter? I don't think it can so it would need it's own puck. I had to install the pitot years ago when I put on the Imco shorty. I got the spring loaded one so it can't get torn off the boat from debris or seaweed.

You can use the NEMA output from your chart plotter to provide a signal to the GPS speedo. That way, you only need to buy the gauge for about $200-$250 or so.
Eddie

I have always been curious about the same thing. I used to hear all kinds of stories. I took my boat apart before I ever had a chance to test with/without. Something to remember about GPS is reading speed over the ground versus a pitot which is showing water speed.

Where I grew up (Lake Michigan) in most cases the difference was of no consequence as there was not much current or tide. However down here the gulf stream average is about 4 mph, so running in opposite directions would give you an 8 mph spread.

Gaffrig (the original, may he RIP) tested his first speedos on my old Cig. We bought a radar gun and did runs up and down the Chicago River. They were amazingly accurate. It all depends on the quality and calibration of the gauge that is used.

It was also lots of fun to cruise down LSD, turn the radar on and watch the sea of red tail lights as everyone's radar detector maxed out.

Good stuff. Thanks Eddie, Marc.