In dash GPS speedo?

[harringtondav]

Very happy with our new Regal 1900ESX. Like most pitot tube speedos, ours is off by a mile. I recently whacked some debris and plugged the lower unit pick up hole. I removed the plug and got a nice stream of water, but the gage is stuck at 20 mph min.
So I'm looking at tearing into a brand new dash to investigate, repair or replace. I'd rather replace with a GPS speedometer if available. The current speedo is a Faria 33839.
Does anyone know if GPS speedos this size are available?

 

[briangcc]

I'll admit it, you have me confused as 33839 from Faria is a 4" GPS speedo 0-60mph. You sure of the part number??

 

[harringtondav]

I'll admit it, you have me confused as 33839 from Faria is a 4" GPS speedo 0-60mph. You sure of the part number??

Thanks. Seems I was also confused. I decided to do some self help and found the same Faria p/n. ....looks like I'm set with a drop in replacement.
I'm away from the boat for a few days. After I verify size and existing wiring I plan to order this.

 

[Lou C]

Maybe you could just replace the pick up for the pitot tube. I did that & cleaned out the hose for it and the Speedo follows my gps speed over 10 mph….

 

[Renken2000Classic]

If it's frozen at one speed, sounds like there's a clog.

 

[Lou C]

Disconnect the the tube from the pick up & bow it out with compressed air. That’s all I had to do and my boat sits in salt water 5/6 months each season

 

[harringtondav]

Maybe you could just replace the pick up for the pitot tube. I did that & cleaned out the hose for it and the Speedo follows my gps speed over 10 mph….

The pickup is in the front of the lower gear case. VP. Unlike my old Apha II the tube disappears into the gimbal housing somewhere. I followed it up inside the dash, disappearing into the speedo gage. No room to work, so I'll have to remove the speedo gage to remove the tube/hose. I can then see if the tube is blocked or the gage is bad.
It's all warranty, but it will be Oct before the dealer will look at it. ..thinking I'll do a better job not buggering up the nice black trim screws. By the time I go through the trouble to get the gage out I'll drop in a Faria GPS replacement and move on.
BTW, when the speedo was working it led my phone's GPS by at least 5%. I've got a new prop and want to easily measure slip. Fumbling with a phone and avoiding channel markers is a pain.

 

[harringtondav]

If it's frozen at one speed, sounds like there's a clog.

It sets at 20 mph, then rises from there, and drops back to 20. Per my other comments, I'll spring for a GPS speedo and be done with it. Pitot tube speed readings are a general indication of fast or slow.

 

[tpenfield]

All the cool kids have GPS speedometers. So, I think you will be well served by upgrading. I don't even bother to hook up the water pressure speedo . . . only to have it last about 2 outings before it gets clogged.

The VessesView (SmartCraft) system on my new-2-me boat has a GPS speedometer along with fuel consumption metrics, although I don't like looking at that part of the system

 

[JimS123]

Buy a cheap GPS hand held and mount it to your dash with a Ram Mount. Or, replace the pitot and tubing and it will run spot on.

My 1952 classic on an oldie boat runs equal to my GPS, and all I did was replace a rubber tube.

 

[JimS123]

All the cool kids have GPS speedometers....... only to have it last about 2 outings before it gets clogged.

Yes its cool. But if it gets clogged its because there is an air hole in the tube.

35 years on a pitot and it was spot on even after all those years.

 

[nola mike]

My pitot speedo was accurate to within 1-2 mph @ upper 40's. Replaced with a GPS unit to eliminate potential water entry points in the transom. Biggest issue is that it takes a while to get a fix ... But it's super cheap, so...

 

[jimmbo]

Be Aware that the GPS will be giving you a Ground Speed, not a Water Speed. If there is a Current, you will find the boat going faster in one direction, and slower in the opposite.

 

[tpenfield]

Be Aware that the GPS will be giving you a Ground Speed, not a Water Speed. If there is a Current, you will find the boat going faster in one direction, and slower in the opposite.

Yes, when making the 'speed runs' to verify WOT speed, it is advisable to make a pass in both directions to be able to net out any current.

 

[dingbat]

Be Aware that the GPS will be giving you a Ground Speed, not a Water Speed. If there is a Current, you will find the boat going faster in one direction, and slower in the opposite.

This is one of those things you hear repeated that makes absolutely no sense in practical terms

I’m anchored in a 3 kt. current. My paddle wheel (water speed) says I’m doing 3 kts per hour. My GPS says I’m not moving.
Which is right?

Traveling the 96 nautical miles from Chesapeake Beach to Norfolk. I’m running at 30 kts gps and the tide changes roughly every 5 hours and 59 minutes.

How long is it going to take me to get to Norfolk?
How long to get back!

Yes, I’ll need to increase the boat’s rpm to maintain speed against a current but that doesn’t change the fact that I’m making head way at 30 kts.

 

[JimS123]

This is one of those things you hear repeated that makes absolutely no sense in practical terms

That is exactly what IS practical. Going one place to another is one thing. But if you are doing a performance curve on a boat the GPS is worthless.

 

[harringtondav]

All the cool kids have GPS speedometers. So, I think you will be well served by upgrading. I don't even bother to hook up the water pressure speedo . . . only to have it last about 2 outings before it gets clogged.

The VessesView (SmartCraft) system on my new-2-me boat has a GPS speedometer along with fuel consumption metrics, although I don't like looking at that part of the system

I've thought about a fuel consumption monitor, but no real need. We mostly boat between two Mississippi river L&Ds, 19 mile pool with plenty of gas docks. ...wondering if a consumption monitor could be programmed in $/mile. But at today's gas dock prices that would just be a wet blanket on the whole experience.
BTW, your Cruisers looks like a nice replacement of your old Formula.

 

[nola mike]

Be Aware that the GPS will be giving you a Ground Speed, not a Water Speed. If there is a Current, you will find the boat going faster in one direction, and slower in the

Edit misunderstood

 

[nola mike]

Yes, when making the 'speed runs' to verify WOT speed, it is advisable to make a pass in both directions to be able to net out any current.

That holds true regardless unless there's no wind where you live

 

[dingbat]

That is exactly what IS practical. Going one place to another is one thing. But if you are doing a performance curve on a boat the GPS is worthless.

I’m in the measurement business. You would be amazed at how many customers (experts) spend big money for instrumentation with far better performance than needed to met their need with little to no ROI

In that line of thinking…given the wide range of recommend WOT rpm and that most props are only available in 200 rpm increments, how accurate do the speed and rpm readings need to be to prop a boat?

What speed device do you recommend to met the accuracy criteria knowing “over the water” speed devices are notorious for speed and linerity issues?

Don’t you need a anemometer input as well?

Would you not remove or minimize any effects of current by simply running your test across the current?

From a practical stand point, what does a “performance curve” buy you other than a nice graph to display?