Project – Provide speed control for my boat
Boat – Monterey 194FS
Mercruiser 4.3L MPI 220hp

Scenario:
My boat is a very competent runabout, but as with all I/O holding it at a constant low speed is not easy, with the rider often having his arms pulled out of the sockets on a start, and speed ranging widely making a run very hard work.
The answer is speed control, similar to cruise control in a car (and in fact will work in that mode), can keep boat at same speed, allowing driver to concentrate on driving and not constantly looking at speedo and having top make throttle adjustments.
When rider puts on a lot of pull when cutting, again difficult for driver to keep things constant.
Options:
Initially speed control was by RPM only, boat attempted to keep constant by increasing power by monitoring RPM of engine, the next step was with a hull mounted paddle wheel that sent a signal to a push pull unit that controlled throttle linkages.
Technology has moved on somewhat, systems are small, digital, reliable ….. you can still have paddle wheel systems, however with increased use of very accurate GPS systems you can get full control with no need for a paddle wheel, making install much simpler (not everyone wants to drill a 2” hole in hull, or problems of a paddle wheel & trailering.
As with everything there are pro’s & con’s … if you ski on a calm lake then GPS is perfect, if you ski on a river with significant water flow, then GPS may not be ideal.
The reason here is that a paddle wheel measures speed over water, GPS measures speed over ground, if there is a current running then speed over ground will be impacted positively or negatively depending if you are running with or against the current.
There are 2 real contenders on the market, ‘Perfect Pass’, been market leader for some years, and in use on majority of tournament boats, their StarGazer system being the GPS variant.
http://www.perfectpass.com/?q=systems
A couple of years ago a young upstart appeared that listened to the wants & needs of riders, and brought out “Ridesteady”, initially a paddle wheel only, and now a GPS based system.
http://www.hydrophase.com/systems
Cost wise Ridesteady is about 10% cheaper, plus a $100 cash back if you send in pictures of install.
I took a good look at both systems, in terms of what they do in controlling speed there was no difference ….. however what swayed me (easily) was the totally different control unit …….. in both systems you replace a standard gauge with the manufacturers
Here is “Perfect Pass”

Here is “Ridesteady”

In my case it was a very simple decision based on ergonomics and ease of use ….. the rotary dial allows very quick scrolling thru menus, and it’s also a button …. Very intuitive & easy.
When you are towing if you want to adjust speed up or down just simply turn the knob, …. The display always shows current sped in large numerals, and underneath is set speed, so you can see easily what you are doing.
The “Perfect Pass” unit requires multiple pushes of buttons to make changes ….
Bonus parts –“Ridesteady “include air & water temp sensors for no charge, so you end up with a comprehensive display showing:
Time, Speed actual, Speed set, Rider, water temp, air temp, RPM and a digital compass.
It also allows you to set up profiles … either by rider name, or in my case I have it set currently for the sports …. Skiing, SkySki, Kneeboard, Wakeboard.
If you set by name .. it will show duration of last run for that rider and cumulative total to date.
What is in the Box
- System Control unit
Motor unit & chassis
Display console
GSP module
Water temp sensor
Air Temp Sensor
All cables (plug terminated)
A bag of assorted fittings .. to cover all types of throttle connection.
Fully printed & bound manual.
Install
First off – you contact “Ridesteady”, the owner Justin answers email in minutes, and is always there on the phone. You tell him the engine type, and he will send you colour pictures of a completed install so you know how to set up throttle control.
First job is to clamp the motor unit, this is a stepper motor already fitted to a chassis,

You plug in the motor control lead, cable tie it …. The recommended location is on one of the large hoses that attach to exhaust risers.
Simply loosen front and rear clips, slide mounting tags of chassis under & tighten up.
The throttle control cable is pre-fitted, you route this to the throttle linkage in a smooth curve – no clips needed.

Throttle position on starboard of the 4.3L MPI engine

which has the following Linkage

Throttle cable addition.

It took me a while to understand what I was trying to achieve … in simple terms you are removing existing throttle cable (that goes to your control lever) .. the control cable from stepper motor then connects to your throttle arm, and your existing control cable attaches to this.
A bag of brackets and fixings allow you to choose whatever alignment works for you …..the manual shows a selection, but the picture “Ridesteady” emailed was a match for my engine so I copied that.
You then simply adjust the existing throttle linkage (by rotating the brass barrel)until all play taken up on the control cable wire.
You then move throttle from neutral to full throttle and back and check all play remains taken up … minor adjustment to stop to achieve this.
Difficult part of job done.
Important (and not immediately obvious to me .. the stainless bracket that attaches the control cable to throttle is not done up tight, it must be allowed to swivel, so cable keeps aligned as it travel through opening arc of throttle.
You then run the stepper motor electrical cable back to under the dash … in my case I decided to run in a length of flexy conduit .. so if I ever want to add cables in future it’s easier ….
I run the cable round the back of the engine clipping it with cable ties to an existing conduit, helps here to have a skinny teenager you can wedge into engine bay (Thanks Jordan) Having put in conduit I used a draw tape to pull through the control cable ….
n.b . you need to specify a 14’ cable if you are doing an I/O install
This is resined into an escutcheon plate, if you have an existing lever pitot tube speedo, you could simply remove that tube and use that hole …. I didn’t so drilled a 3/16” hole thru transom. The water temp cable is supplied terminated but not into the plug, to allow you to use a small hole.
Be warned the terminals are not very robust, and pulling them though flexy conduit could damage them … I placed a spare piece of tubing over mine held in place by insulating tape to protect them when being drawn.
The sensor itself has a piece of 3M VTB bonding tape … so just clean hull with isopropyl alcohol and stick it on .. route cable through hull and seal hole with marine mastic.

I am obtaining a spare escutcheon plate so I will cover cable entry point, so it will match sensor.
Inside engine bay this cable is again routed along existing conduit and then drawn through my flexy conduit to dash.
That is it at that end of boat.
At dash end …

Module, find a suitable place with as clear overhead as possible … for most that will be on top of dash … now a point here, the attached plug is just over ½” wide …. Didn’t fancy a ½” hole, so I removed plug … easy to do with a very small screwdriver (and note where colours go)
This allowed a smaller hole, to which I inserted a grommet, cable passes thru and GPS module has an adhesive pad to stick in the desired location

Remove chosen gauge …… now you need to give this thought in advance ……… as when you order you can choose from different sizes & finishes.
I went for 3.5” with stainless bezel to match existing gauges.
I chose to replace the Tacho ….. mainly as the speedo also has the trim gauge built in it on my boat and didn’t want to lose the trim gauge.
The “Ridesteady” console include RPM display so made sense to use that.
You need to insulate the cables you remove, you could ‘cheat’ and use the + and – cables here to power up the “Ridesteady” System Control unit, but I chose to use proper fuse protected feeds (as per instructions)
The display functions:

System Control Unit ...
The unit is screwed to a suitable internal surface behind the dash, the power cable is connected up to 4 locations ….
# a permanent power connection
# a power connection only live when ignition on
# Ground
# Tacho feed signal (grey cable removed from Tacho)

I could not find any supplier locally who stocked these ….. but got them form ebay for £1.95 for 10
The Tacho connection is made by using a ‘scotch lock’ crimp on tap …………. This was an issue for me, fitted tap as per instructions.
On the on-water test the RPM display did not work, checked and “scotch lock’ was correctly fitted …. Just assume that the difference in the 2 cable diameters did not suit. Removed the “Scotch lock” and put a male & female spade connecter on the appropriate cable ends …. RPM then worked fine.
A general point on using crimp connectors … while spade connectors (aka Lucar connectors) they may be fine for use on cars … I don’t like them as standard on marine connections. So I took extra step of using Silicon repair tape .. stuff you stretch as you wrap and its self amalgamates.
This made sure that the cable to sleeve connector was supported & protected on each connection.
Air temp sensor - exactly same as water tempo sensor, you just cable tie this to a suitable location behind dash to allow it to hang in free air. If it reads too warm, there is an offset adjustment in settings to correct.
Al that remains then is to plug in the cables into “System Control unit” , and take care to tie up cable bundles so they put no strain on connectors.
You are advised to put control and power together and the rest in separate bundle …
Install complete
Setup ….. this was so easy – real easy.
You go to the stepper motor and hand wind in the slack of the operating cable, until there is no gap – then power on ignition and stepper motor should vibrate slowly as it checks for slack.
Operate throttle through range and then when back to neutral that there is no gap in cable
Setup of console …
This is all about personal preferences ….
Celsius or Fahrenheit
Temp offset if required
You can also adjust parameters on aggressiveness of response – I left all those at default.
You can then create profiles as required.
The profiles are great each rider has his own kneeboard, wakeboard, profile for speed, aggressiveness of keeping to speed, overshoot etc.
In use.
You chose rider profile … engage gear and drive off as normal, when you reach set speed you go a bit further on throttle and it takes over simple as that.
It works by speed reduction, so going past running throttle position gives it a ‘window’ to operate in, if there is not enough throttle it will show “More gas” on screen.
In practise I find that you start as normal and you are smoothly accelerating, normally to point where you would back off throttle to prevent overshoot, now instead of backing off let “Ridesteady take over.
Between runs when you power off engine the non-switched power feed keeps unit active and maintains GPS lock so it's ready to go straightaway.

and in standby mode

Conclusion ………….
Certainly a DIY install, follow the pictures.
Great in use – makes a vast difference to pull for riders.
If in time I find that it is not accurate enough for me (in-shore use) I can always add the paddle wheel, you would just unplug water temp sensor and plug it in there, paddle wheel has its own in-built temp sensor.
Also when I change my boat if new owner won’t pay for this, I can unplug it reconnect throttle cable and refit Tacho …. And take system to new boat.
I bought mine direct form Hydrophase in the US ..... if you want to buy one in the UK, then one of our forum members will be happy to supply and if you want install .... contact Maven Marine http://www.mavenmarine.com/
Addendum … after using for a few weeks – can honestly say this has increased my SkySki riding by a factor of 50 … instead of my driver struggling to keep speed right and me being pulled off the SkySki … ride is now rock solid – fantastic difference in pull & ride – so smooth.
My driver also loves the fact he no longer has to worry about speed – just starts off as normal and then concentrates on where we are going, Ridesteady does the rest – superb investment.