I am sick and tired of the traditional "hydro" speedometer getting the line clogged, etc. Most of the time, my speedo does not work, because the pick-up in the outdrive gets clogged, or the hose comes loose or (you name it).

Right now, I use the GPS for speed indication. I am wondering if there is a retrofit package that would convert my traditional speedo to a GPS speedometer.

I have Googled to a few things, but I am wondering if someone out there has already 'traveled this road'.

Thanks for any insight/info.

BTW - FWIW - my boat has VDO brand guages

I swapped out the standard cobalt speed and tach with a Smartcraft SC1000 speed and tach for fuel management and its' related information.

I believe it will display either pitot or GPS provided information for speed. I use the pitot to feed speed info to the gauges since my Garmin 176c doesn't have a NMEA port for the Smartcraft gauges to use its' GPS data.

Very happy with the Smartcraft system. Check out the link for more info:

http://www.mercurymarine.com/otherproducts/smartcraft/smartcraftataglance/components/gauges.php

The original is simply a pressure gauge. I doubt there's a kit, sorry to say.

Pop the old one out and replace it with a Lowrance LMF-400 and a paddle wheel sensor. This way you have both GPS (speed over ground) and speed over water data still available and no chance of clogs. All the other features of the LMF 400 will be welcome as well. I am particularly fond of the stupendously accurate gas gauge. Should run about $200 to $225 for parts and shipping.

You can go with the LMF-400 (or LMF-200), or you can buy a Garmin GMI-10, which displays GPS speed (or NMEA-0183 or NMEA-2000 enabled paddlewheel if you prefer).

I installed a Garmin GMI-10 on my boat earlier this spring.

GMI multi purpose gauge.

The GMI can use either GPS or Paddlewheel as its source for speed. In addition, many other parameters can be displayed, such as fuel flow, fuel tank, depth, compass, water temp, and so on provided you have the sensor. The beauty of the GMI-10 is that it can display both NMEA0183 and NMEA2000, so you can put a NMEA0183 GPS on the unit without having to install a NMEA2000 network.

Here is the gauge indicating GPS speed. Note that Max and Average speed is also tracked. While this looks like a real analog gauge, its in fact a computer generated screen - very nice indeed.



And the same gauge (different day) indicating waterwheel paddle speed.



And if you add a network with the correct NMEA0183 or NMEA2000 sensors, you can also display:

Heading. I cannot remember if this is from GPS or my fast-heading compass. But for some of the gauge displays, you can select the source (as shown above for the GPS/Water source for the speed display).



Water Depth and temperature:



Fuel tank levels:



and more (depending on the sensor) ...

The real issue though is where to put it on the dash. If it won't fit, then I would recommend the Lowrance LMF-400 as Dave did. However, the basic differende is that the LMF-400 will fit into a round 3 1/2 gauge opening, but is not in color, and is NMEA2000 only. Otherwise, they basically do the same thing, albeit the LMF-400 is a bit cheaper.

But the LMF-400 will also (with the correct sensor) display Bennett trim tab settings, which the GMI10 won't do. I am using a Lowrance LMF-200, similar to the LMF-400 but in a 2" gauge size, for displaying the Bennett trim tabs. Actually, I have both GMI-10 and LMF-200 (and Raymarine C-80 for that matter), connected together for displaying any of the available parameters on board.

Some of the gauge functions on the GMI-10, as well as the LMF-400 can either display as a gauge or a number, depending on your preferences. But some parameters can only be displayed only as a number.

So the selection between the Garmin GMI-10 and Lowrance LMF-400 comes down to cost, displayed functions (i.e. the LMF-400 can display tabs), source (i.e. the GMI-10 can display NMEA0183 and NMEA2000 where the LMF-400 is NMEA2000 only), or ease of mounting (the GMI-10 is a 4" square gauge, while the LMF-400 will fit into a 3 1/2" round gauge opening).

But for me, I have both (well, both if you substitute the LMF-200 for the LMF-400).

And I plan on adding more NMEA2000 stuff next year - specifically, fuel flow.

To save myself a bunch of typing.
A thread from the Taylor Boat's Roost, started by my mentioning my GPS Speedo in the dash.

GPS Speedo
My Nordskog Speedometer. Model HDG200.



It doubles as a Tachometer, digital compas, and voltmeter.

$400 (Ouch).

Livorsi makes analog display ones too.

I saw Nordskog also has analog GPS speedos. Those might be the simplest solution. Looks like they have their own GPS receiver, so probably not much difficulty for installing.

Looks like you have several options here.

Look What I found !!! A DOPPLER SPEEDOMETER (What's a Doppler Speedometer ???)

Matches my existing gauges
---------------------------------------------------------------



VDO VANGUARD DOPPLER SPEEDOMETER
The Vanguard Doppler Speedometer utilizes
microwave, radar-based speed sensing technology to
provide precise speed readings from 2 to 50 mph.
Using a single transducer, transom-mounted above the
waterline, the Vanguard Doppler Speedometer offers
unmatched accuracy at all speeds and conditions.
Vanguard Doppler eliminates clogged, bent, or failed pitot
tubes and troublesome paddlewheels. Each kit contains an
electronic analog display head and a transducer with 30’ of cable.
---------------------------------------------------------------

No more clogged pitot tubes for me. This is totally awesome.

Anyone ever seen these things (doppler speedometers)? I wonder if they are any good.