Autopilot Quandary

Nov 18, 2010
2,441
Catalina 310 Hingham, MA
So I have had my head in the computer reading autopilot reviews and looking at what would be necessary to install a linear drive unit on our 310. I have hit an analysis paralysis stage.

Our ST4000 isn't cutting it. When we get out in the trades it can't hold the course and gives error messages. This seems to even happen when I have her well balanced and sailing with the wind instrument calibrated correctly. You definitely can't use it to just hold a heading because the winds shift enough that the sails get unbalanced and the unit fails.

I was thinking I would do a Raymarine EV-200 unit with the linear drive. This seems to be a pretty robust and bullet proof system. It would also give another way to steer the boat if the wires or chain for the steering system were to fail as I would install it with . But this will come at a cost of a little over $4k plus lots of work.

I started reading reviews of the Raymarine EV-100 wheel pilot. A lot of the reviews say that the software for the sail units is a big improvement from what is in the ST4000. And the improvement may be enough for it to work on our 310.

So does anyone have experience going from the St4000 to the EV-100?

Thanks,

Jesse
 
Oct 22, 2014
20,992
CAL 35 Cruiser #21 moored EVERETT WA
Jesse, I installed a new EV100 last year. A great upgrade.

Your boat is about 10K Displacement. My Cal is 15K. You have a 5.75ft fin keel draft a little bit quicker to turn then my 3/4 keel 5ft draft.
I can sail balanced in 15knts. Up wind, on a reach all ok. Down wind and a following sea, not so much. Under power Ok.

For me the issue is the motor. While it will slave away and is gentle on the batteries there are practical limits to the EV100 motor. The limits include power and belt drive on plastic.

Except for the time I put a boom box over the cabinet holding the (Startrek compass thingy - That is the technical description) and my boat proceed to do a Crazy Ivan, the unit has been solid.

The display lets you add 3 SeatalkNG connected sensors to the course AP info displayed. Nice to have depth available with course data.

Your boat would handle changing conditions under the AP better than mine due to the displacement. f you really want to sail the trades on open water you need to look to a windvane system. More versatile and capable of going all day and night no power needed. You can also get the "emergency rudder" function as a feature or an add on depending which product you choose.
John
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
I installed the EV200 on my Mk1 C36. Cost was ~ 2600 all in including tiller and wires. The hardest part was drilling the rudder post. I don’t know the space constraints on the 310, but know the Mk1 is a more challenging install than the Mk2.

One thing to check with the 4000 is to make sure you’re getting good voltage while motor is running. Lots were installed with marginal wire - then connectors get old and things don’t work as well

Good luck!!!
Les
 
Nov 6, 2006
9,884
Hunter 34 Mandeville Louisiana
Another ST 4000 thing is a rudder reference device.. My ST 4000 handles the 34 well after I installed the rudder reference thingie.
 
May 25, 2012
4,333
john alden caravelle 42 sturgeon bay, wis
sea state is what knocks a vessel off course. the wind can be a steadying factor. you wrote that it is in the trades that your auto pilot can not keep up. this implies big waves for a 31 ft vessel. 31 ft trade wind designed vessels do not look like a cat 31. john said his boat, which is more streamline then the cat 31 is good to 15 knts wind. that is not trade wind conditions. i looked up your boat on saildata. i read what you wrote on your web sight of what the designer told you he was trying to achieve with that design. your words did not imply a trade wind type of design. while great on the hook or at the dock. delightful in non trade wind sailing. all vessels reach a point of sea state to which they need to turn off the auto pilot and hand steer. i suggest to you that you prolly won't get any autopilot to handle trade wind sized sea state with your design.

call up your designer, ask him if what your wishing for is doable. crealock style sailboats are more tradewind friendly then the design intentions of your 31.
i agree with john, your best chance might be a wind vane set up. but still, i would not count on it.
 
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Oct 22, 2014
20,992
CAL 35 Cruiser #21 moored EVERETT WA
Claude.. That is a very helpful tool. One of the issues with my EV100, while surfing down a wave, it looses the angle of the rudder and takes a bit of time to decide where it should be. Then the motor tries to come on and correct, but by then the wave is pushing the rudder and the AP is behind the power curve to correct the boats heading.
That's when the manual control springs to the rescue.
The Rudder thingie would help. I think @mainesail makes it a requirement on his AP installs.
 
Nov 6, 2006
9,884
Hunter 34 Mandeville Louisiana
John, I fiddled with my ST4000+ for about three years before I put the rudder reference in the loop.. I could get it close, but the low number of turns, lock-to-lock, would quickly confuse the thing..
 
Aug 2, 2009
637
Catalina 315 Muskegon
I've been in the same quandary with my Catalina 28. The original st4000 from 1996 isn't worth fixing. Considered the EV100, but as I research it, there are a lot negatives with regard to installation and support from Raymarine. And to update the software you have to have a Raymarine chart plotter!?!?

I happened to stumble across the CPT autopilot. They don't interface with anything, but are apparently a fairly robust wheel steerer. I called the company and one of the owners answered the phone and discussed it with me. I'm ordering one this spring. Installation is a breeze. The only downside, which isn't a downside for me, is that it doesn't interface with anything (gps, wind direction, etc.). They started making them in 1996, and there have been a few different owners, but the current owner has been making them since 2007...something to keep in mind as you read stale reviews. About $1800.00.
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
. And to update the software you have to have a Raymarine chart plotter!?!?
00.
The other option is to have a good friend with a Raymarine CP - that’s what John does :biggrin:

You can also send it back to RM to update (don’t know if thy charge).

Firmware updates have slowed way down for anything but Axioms
 
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leo310

.
Dec 15, 2006
635
Catalina 310 44 Campbell River BC
I install the EV-100 with rudder thingie and found that it stopped hunting to maintain track as before the rudder thingie was installed. Have been in 15-20kt winds with no problem in control but as mentioned before this unit need power so don't under size the wire.
 
Oct 9, 2008
1,739
Bristol 29.9 Dana Point
The issues I've had with Raymarine are with the control head/software. Not relevant to drive config. I have the X5 with P70 head.
1. They removed the "resume" function. So if I go to standby (for numerous reasons) it doesn't remember the previous compass heading. This blows because the previous heading might have been perfect for the sail sheeting. So I have to either remember the heading and reset it, or more likely I have to monkey with it to find the perfect heading again. - I don't have NMEA wind-angle ability from my anemometer.
2. The auto calibration doesn't set up the config correctly. Too much of this or not enough of that, type of thing. You have to experiment manually to get it to be stable at usual sailing speed. Took me awhile, and had to tweek it even months/years later. I finally have it perfect.
3. In "Track" mode, where it follows a GPS waypoint, it demands the boat stay in a straight-line track from the start point to destination. No setting to correct this. This causes the pilot to steer, sometimes radically, back towards the track if you get too much leeway, upsetting the sails or even backwinding them. This is fine for a powerboat, especially in a designated channel, but an idiotic pain sailing on the open ocean.
My old Simrad tiller pilot would always point the GPS heading towards the GPS waypoint in "Track" mode, regardless of position. This might mean gradually steering up at times to compensate, but not the periodical radical shove back to the track line.
The only way to fix this is to set the response level high to keep her rigidly in the track, but then you have the drive constantly steering, wasting power and annoying the skipper.
So I only use track mode if the wind is on the beam enough to keep the sails running during an upswing. Then it's barely noticeable.
 
Last edited:
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
Jesse, I installed a new EV100 last year. A great upgrade.

Your boat is about 10K Displacement. My Cal is 15K. You have a 5.75ft fin keel draft a little bit quicker to turn then my 3/4 keel 5ft draft.
I can sail balanced in 15knts. Up wind, on a reach all ok. Down wind and a following sea, not so much. Under power Ok.

For me the issue is the motor. While it will slave away and is gentle on the batteries there are practical limits to the EV100 motor. The limits include power and belt drive on plastic.

Except for the time I put a boom box over the cabinet holding the (Startrek compass thingy - That is the technical description) and my boat proceed to do a Crazy Ivan, the unit has been solid.

The display lets you add 3 SeatalkNG connected sensors to the course AP info displayed. Nice to have depth available with course data.

Your boat would handle changing conditions under the AP better than mine due to the displacement. f you really want to sail the trades on open water you need to look to a windvane system. More versatile and capable of going all day and night no power needed. You can also get the "emergency rudder" function as a feature or an add on depending which product you choose.
John
Thanks for the reply.

Just so you know, you are a little off on the specs for the 310. With the wing keel the weight is closer to 11k with a draft under 5 feet. And that's a dry weight. With fuel, water and loaded for cruising I'm closer to 13-14K.

I don't think the windvane is really a solution. With the open transom and the fuel tank mounted under the sugar scoop installation is near impossible. Plus I would still need an AP for motoring when the wind drops in the summer.

What you pointed out with the motor and belt is my concern. I have gone through a couple of belts in the last couple of years and I'm not very thrilled about the quality of what I see. That's what had me looking at the below deck to begin with.
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
Claude.. That is a very helpful tool. One of the issues with my EV100, while surfing down a wave, it looses the angle of the rudder and takes a bit of time to decide where it should be. Then the motor tries to come on and correct, but by then the wave is pushing the rudder and the AP is behind the power curve to correct the boats heading.
That's when the manual control springs to the rescue.
The Rudder thingie would help. I think @mainesail makes it a requirement on his AP installs.
Absolutely. Either system would have a rudder angle transducer. That seems to be one of the keys to the better downwind with following seas performance.
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
sea state is what knocks a vessel off course. the wind can be a steadying factor. you wrote that it is in the trades that your auto pilot can not keep up. this implies big waves for a 31 ft vessel. 31 ft trade wind designed vessels do not look like a cat 31. john said his boat, which is more streamline then the cat 31 is good to 15 knts wind. that is not trade wind conditions. i looked up your boat on saildata. i read what you wrote on your web sight of what the designer told you he was trying to achieve with that design. your words did not imply a trade wind type of design. while great on the hook or at the dock. delightful in non trade wind sailing. all vessels reach a point of sea state to which they need to turn off the auto pilot and hand steer. i suggest to you that you prolly won't get any autopilot to handle trade wind sized sea state with your design.

call up your designer, ask him if what your wishing for is doable. crealock style sailboats are more tradewind friendly then the design intentions of your 31.
i agree with john, your best chance might be a wind vane set up. but still, i would not count on it.
Thanks but I didn't ask for boat recommendations, I asked for reviews on autopilots. I have been sailing my Catalina 310 in the trades for several years now. The boat has zero issues with conditions. In fact I am typically beating most of my friends with the "trade wind designed vessels" into port on passages. I would actually argue that the 310 is better designed for sailing the trades than a Crealock style double ender. The style of boat you are advocating lacks reserve buoyancy in the stern, so when those big following seas start breaking they can get pooped. The 310 lifts up and surfs down. By the way this is also Bob Perry's opinion of double enders, even though he is one of the most well know designers of them. Same can be said for most of the narrow stern "blue water" boats.

The boat was designed to cruise for two people. Nothing in how it was designed suggests its not fit for the Caribbean or beyond with the right crew.

But hey, everyone has there own likes. I like being comfortable and fast. I miss the trimaran I ran before Irma claimed it. Nothing like sailing at 28 knots in 40 knots of wind and 15 foot seas. ;)

Fair winds,

Jesse
 
May 25, 2012
4,333
john alden caravelle 42 sturgeon bay, wis
jesse, i'm alway happy to learn new things. you used the word "argue". i'm shy of that word. how about 'discussion'. of course you vessel would be faster then say a westsail. your vessel is well made. that said. i was talking about vessel dynamics below the water line. nothing in your reply addresses the dynamics of the ability of any hull shape to track straight in a trade's seaway. i'm sure your tri tracked very straight. so, you said your auto pilot was not keeping up with the conditions of the seaway of the trades. a vessels under body shape coupled with the chosen foils will determine how squirrely a given vessel might get as conditions build. the more straight line foils the better. the narrower the hull the better. ALL vessels get to a point where yachtie auto pilots will be useless. just like 1,000 foot ships turn off the auto pilot when the vessel starts working.
all designs are a compromise. you have a wing keel. it will never track like the deeper fin option. it will never track like a vessel with a full keel. you know that.
you talked sailing in forty knots of wind on your tri. it's obvious a yachtie auto pilot will never drive your 310 reliably in those conditions. so it's some where in between your system, whatever it is, will be overwhelmed. prolly on the 310 before a trade's condition seaway. due to your very wide beam and small foils.
you have a nice boat. it will take you around the world if your are so inclined. but that does not mean your underbody is ever going to be as steady in a big seaway as other designs.
the above the waterline has absolutely nothing to do with how a mono hull tracks. you will always have to start hand steering earlier with your speedster than most.
hey, call bob perry up. he will answer the phone. have him explain it to you if you want.

:)
 
Feb 26, 2004
22,759
Catalina 34 224 Maple Bay, BC, Canada
Jesse most likely has seen this post from his extensive research when he first bought his boat. Many of you may have not.

http://www.c34.org/faq-pages/faq-autohelmwacky.html

while it's a decade old, it still applies generally, even with all the bells & whistles Raymarine has seen to feel fit to add to what is a simple system. I have an old ST3000 that works in protected waters. I would make the choice to get a much more robust system if I was traveling outbound.
 
May 25, 2012
4,333
john alden caravelle 42 sturgeon bay, wis
jesse, i'm old. my first love is sailing. i've been doing this sport for 58 years now. i have well over 1,000,000 miles at sea. i'm still learning. that's why i love this sport. always something new to learn. 27" of ice in my bay today so i have time to share. hey go spend your 5,000.00 and if i'm wrong then let us know. we can all learn then.
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
The EV200 is much smarter than the old 4000. I believe the the 4000 only has a 1 axis sensor (compass) where the EV series has 9 axis sensor so it know and can learn sea state. Comming across the Strait of Juan De Fucia last year 2-3’ waves on back quarter - the pilot got better with time.