Mantus Anchor Upgrade

I was not happy with the stock Catalina Danforth-type anchor. I have had quite a bit of experience with Danforth-type anchors on previous boats going way back, including new versions in the form of a Fortress on my previous catamaran. These anchors work really well in mud, but are unreliable in sand and not effective at all if the bottom is rocky. I want to be able to anchor in open roadsteads up and down the coast and so needed a more modern anchor design.

I did a lot of research (again), and spent a lot of time watching videos made by Steve Goodwin at https://www.youtube.com/@Panope. What an amazing resource - thank you Steve for all of your work! I settled on the Mantus M2 as it was highly rated across all bottom types, ironically less so in soft mud. However, my main anchoring issues in the past have been on rocky bottoms, and I wanted an anchor that was reliable on rocky bottoms even it the performance in mud was not stellar. For example, on several trips to Drakes Bay in my last boat, I had spent much time trying to get a spade-style anchor to hold in the rocky matrix there (I had a spade-type and a Fortress on that boat). 

Mantus M2 with optional Anchor Guard fitted

I ordered a brand new 25lb M2, 60 feet of G43 hi test 1/4" chain, and 250 feet of 1/2" New England ropes three strand. I went with the 25lb because I can haul it up without the winch in case the winch stops working. A 25lb anchor is technically a little undersized for an 11,000lb boat. However, there is an ongoing debate on the degree to which traditional anchor-weight guidelines are overly conservative. There is an emerging opinion that the traditional guidelines reflected anchors with relatively low effectiveness and that were thus dependent on dead weight, rather than holding power. More modern designs (may not) need as much weight and may even be more effective in smaller sizes. The load tests carried out by Steve Goodwin suggest that 25lbs will be a workable size for my Catalina (I am not advocating that anyone else should use this size). If I was going on a lengthy voyage, I may consider taking a larger anchor stowed. The 25lb anchor has since worked out to be more than adequate for most conditions, and has held aggressively in several circumstances with very high loads (5 knot tide plus high winds).

The 1/4 inch G43 Hi Test is rated at 2,600 lbs working load (7,800 lbs 3:1 breaking load); the New England three strand line is rated at 7,500 lbs tensile (breaking) load. I used 1/4" G43 because that is the correct chain sizing for my winch gypsy. For a boat the size of the 320, 5/16" chain would be desirable - however, the 1/4" G43 Hi Test has a higher working load than the regular 5/16" BBB chain (1900 lb working load, 5,700 lb breaking load) which is commonly used on many boats. 

The M2 did not fit very well on the standard Catalina anchor roller without help. It is too nose heavy and flopped around on the roller. So I ordered and installed the Mantus Anchor Guard which makes all of the difference. This style of anchor is awkward to stow (due to the nose heaviness) and I have finally perfected the technique of manually pulling the anchor the last few feet into place on the anchor roller - trying to use the winch often caused violent gyrations in the last few feet as the anchor orients to the anchor roller. Once stowed, I keep the anchor firmly in place with a lashing from the end of the anchor to the pulpit, and a lashing over the shaft where is has leverage to balance the nose weight of the anchor. The anchor is very stable, even in heavy conditions, when lashed in this manner.

Line lashed through two bow shackles for extra security when it gets bouncy

Lashing to Pulpit

Installation of the Anchor Guard had its own complications. Because the main mount is the spindle bolt for the anchor roller; tightening the bolt sufficiently to secure the Anchor Guard also had the effect of locking the anchor roller in place. 

                            Anchor roller turns freely on sleeve. Anchor Guard mount is tight.

The video shows how the roller can now turn smoothly on the tube spacer with the through-bolt and Anchor Guard attachment firmly tightened on the bow roller assembly. This was solved by drilling out the center of the anchor roller just enough to provide clearance for a stainless steel sleeve. The sleeve is slightly wider than the roller, and takes the side load when the spindle bolt is tightened to secure the Anchor Guard. Now the whole mounting is tight and secure, and the anchor roller turns easily on its spindle.

I feel that this is a worthwhile upgrade, and the M2 has held firmly in a range of challenging locations e.g. overnights at Drakes Bay, and among the kelp at Ano Nuevo. The M2 is definitely not the right anchor for all conditions - I have had it refuse to set several times in the soft silt at China Camp (Marin) for example. If I had an unlimited budget, I would have an M1 for the soft mud of the Bay, and the M2 as backup for rocky bottoms along the cost. However, it performs adequately in most mud bottoms with plenty of scope. 

Costs:
$345     25lb M2 galvanized inc. shipping and tax (Mantus Anchors)
$137     Anchor Guard Starboard Medium inc. shipping and tax (Mantus Anchors)
$237     60' 1/4" Peerless ACCO Grade 43 Domestic High Test (not inc. tax and shipping) (Defender)
$110     250' 1/2" New England Ropes Premium Nylon Three Strand White 

            (not inc. tax and shipping) (Defender)
$4        1/2" x 4.5" 316 Stainless bolt (McMaster Carr)
$27      3/4" OD 1/2" ID (0.120" wall thickness) 316 Stainless Tube x 6" (McMaster Carr)
$10      3/4" drill (Amazon)

$870    Total (minimum)

CPT Autopilot Upgrade

The standard Autohelm ST 4000 autopilot looked like it had not worked for a long time. The power was disconnected, and the mechanism made rumbling noises when turned. 

Initial bracket design attempt from CPT for the 320

I did a lot of research (recurring theme) on different alternatives for a new autopilot. Without doubt the best alternative would be a hydraulic ram working directly on the rudder post under the deck. Looking on Catalina.org I found that other folks had successfully made this upgrade. This option was the most expensive and the most complex, but would also be the most fit for purpose. I want to do long coastal cruises and perhaps ocean crossings, and the ram designs would excel at these tasks, and are very strong. However, I needed something quick, and did not want to pay a technician $150 an hour to get all of the wiring and electronics working.

Design Mk I Was too close to both the wheel and the pedestal mount.

I considered the Raymarine EVO 100 wheel-mounted autopilot, which appears to be the most common upgrade, but was put off by conflicting reports that they are easily overwhelmed under sail. I finally settled on the CPT autopilot after reading many glowing accounts about the robustness of this system, and because I could install it myself without worrying about complex electronics. In the end, I was much more concerned about robustness and simplicity, and the claims that the CPT could cope with stronger conditions than other wheel-drive mechanisms. At time of writing, the CPT has been installed for more than a year and has several hundred miles of coastal use, and I have mixed feelings about its overall effectiveness that I will discuss below. 

Fitment mark II. Success! 

The install

The CPT had not been previously installed on a 320, so this was a trial and error process with continuous support from the company. The first kit was supplied based on my initial measurements, and was almost there but resulted in interference between the motor drive wheel and the steering wheel, and between the CPT mounting and the pedestal foot. To cut a long story short, the Mark II version solution was to include an intermediate drop down plate and a longer belt. The Mk II provides just enough clearance in all directions. The belt still runs very close to the rim around the instrument panel box, and I judiciously cut the box away to let the belt run free (see pics below). It takes some finagling to get the mount orientated on the pedestal so that the drive belt does not hit the wheel or the instrument panel housing. The CPT mount is initially held onto the pedestal with hose clamps: once the autopilot had been set up and running for some time with no interference, I drilled and tapped screws mounting the bracket permanently to the pedestal.

How well does the CPT work on a 320?

Caveats: I almost always sail solo, so the review would be different if there was more than one person to reef and trim sails. The effectiveness of equipment is subjective, and the descriptions of conditions are subjective. I have been sailing for a long time and believe that I tend to underestimate wind speed and wave action (and my Autohelm Wind Speed Indicator is not currently reading accurately). I was also a marine fitter in a previous life and am thus critical about mechanical gadgets. The point being that my assessment might be a bit on the critical side - for example, when I think it is gusting to 15 knots, perhaps it is actually gusting to 20 knots?

It is quite tight all around, but works fine and is reliable. Note that the edges of the instrument panel are cut away to clear the drive belt on both sides.

Tight, but works.

Tight, but all fits and works.

On the 320, the CPT as currently configured is fit for purpose up to around 15 knots true wind speed with some sea state - no problem. However, I had hoped, perhaps over optimistically, that it would be a set and forget solution in 25 knots - this has not turned out to the case; though I am still working on it.

I have seen reports saying that the CPT works flawlessly on boats much bigger than mine at 20 plus knots in blue water. But is that 20 knots true or apparent? Is it beating or running? How big were the seas? Is it a boat with a long tracking keel, or a flighty fin keel? I have found that in 20 knots of true wind speed and moderate sea conditions the CPT struggles to cope. If the sails are not carefully trimmed, the loads will make the drive belt jump off the motor - this is not a crisis and CPT consider this to be safety feature of the design. When this happens the belt has to be refitted and tensioned. However, it is not ideal when sailing alone to have the autopilot suddenly stop working, and having to take control of the boat in windy conditions, while also trying to reset the drive belt on the autopilot.  Looking through the lists of boats with the CPT installed, it seems that it was originally designed and used by boats with longer keels and more stable tracking than fin keel boats like the 320. I find that I have to have the electronic settings on minimum rudder gain and damping to get reasonable performance on the 320. This makes sense if the original design was for longer keel, stable-tracking, slow-turning sail boats. 

Another factor is the design of the 320. I have been surprised by how much weather helm it has. My boat does not have excessive mast rake, yet has significant weather helm when powered up in 15 knots with full sail. It is not uncontrollable obviously, but just more than I expected for a modern fin keel boat.

With control unit.

The toggle switches are + or - 1 or 10 degrees port and starboard. The control knobs are "rudder" turn gain (left), and "deadband" degree of dampening (right knob).

My personal observation in the 320 beating to windward in a moderate sea state with one reef in the mainsail, is that the CPT can handle 15 knots true wind speed + boat speed, so around  20 knots apparent wind speed. On a reach with 15-20 knots true, the steering gets loaded up real quick, even with one reef (mainsail), and the CPT struggles if the rig is powered up - so the power needs to be eased off with traveller and jib sheets until the autopilot can cope. Running in 20 knots true wind speed, the CPT doesn't like much mainsail as it wants to weather vane into the wind. This is exacerbated in a following sea, and the CPT will not cope even with a reef in the mainsail. I find the solution is to drop the mainsail and run under headsail alone. In stronger winds, the boat is approaching hull speed anyway and the boat tracks nicely with the CPT with just the genoa furled to suit.

Powered up in 10+ knots true wind speed - no problem.

So, I had hoped that the CPT would allow me to set and forget the autopilot with reefed sails at 20 knots true wind speed on a long trip. The reality is that it will kind of do that as long as I spend time reefing and trimming the sails to minimize steering loads, and give it frequent supervision. In conditions like this, it will still periodically get overloaded in gusts and the belt will jump on the drive mechanism requiring it to be retensioned / reset.

A major problem with my perspective here is that I have never sailed a 320 with another type of autopilot, so I have no reference point for comparison. If the original ST 4000 had worked, or if I had sailed with an EV 100 wheel pilot, maybe it would be clear which one had the better performance. So for this reason and the other caveats above, please take my opinions with a big grain of salt.

The people at CPT are very responsive, and I will continue to experiment to improve performance. For example, I am going to enquire about modifying the controller program (for flighty fin keel boat balance), and whether a larger drive wheel might be an improvement in windier conditions.

Please let me know in the comments if you have comparable experiences or insights on wheel autopilots - thanks!

Pros of the CPT:

- Saved a lot of money doing the complete mechanical install myself, but it took a lot of persistence and effort to get it to fit and work properly. However, this is the first install on a 320. 

- As above, wired for power myself. Does not require paying someone to solve complex electronics set up and fine tune. 

- Priceless customer support from the company, including both install advice and parts and service. 

-Simple and robust design that works - no non-mission critical bells and whistles to break down.

Cons:
- Not set and forget in 20 knots plus wind speed.

- Pricey compared to other wheel autopilots.

Costs:

$2,462 CPT autopilot: vertical motor box, port reverse pedestal mounting kit, shipping and tax.

$29      Drop down plate, drive belt #1520 17.875”

$?        Wiring, fuses, other bits and pieces

$2,491 Total (minimum)

Head Overhaul

For a workable boat, the head HAS to work properly and be comfortable. The standard-sized Catalina heads are horrible. They are the smallest size Jabsco heads, and are so small that they are difficult to use and very uncomfortable to sit on. The previous owners were day sailors who used the marina pumpout regularly, and had removed the standard macerator pump and hull discharge pipe. The hull discharge valve had not been used for a long time and was seized. I intended to frequently cruise the boat for longer periods, so this was all a no-go for me.

In with the new full-size head. So comfy!

I did a lot of research looking for a better alternative. I did a deep dive into dessicating toilets like the Airhead, which are attractive because of their capacity compared to a holding tank. However, they have a fundamental weakness in that the process of separating waste liquids from solids is not just an ideal, but must be diligently maintained. If the solids compartment gets contaminated with liquids, then the whole process breaks down, and the "dry" compartment needs to be cleaned and reprimed. I was not worried that I would be unable to do this, but think that it is impractical to believe that day-sailing guests will correctly follow instructions and protocols (anecdotal accounts say that they often do not). Thus, I decided to completely replace all of the head plumbing, pumps and valves, and to install a brand new full-sized conventional head.

Out with the old micro seat

I was surprised to find that the full-size Jabsco head is a straight swap with the same mounting bolt arrangement. This made a potentially complex job, a relatively simple component swap. The original blackwater tank was in great condition (thankfully) so there was no need to contemplate the daunting job of a replacement. Instead, with the exception of the tank pump out hose (which must have been replaced at some point) I replaced everything else, including the tank vent hull fitting.

Showing the loop from the pump to discharge valve

As noted above the original macerator pump and discharge pipes had been removed by the PO. I did a lot of research on pumps, and found that macerator pumps are guaranteed to stop working regardless of how expensive they are. So I used a large capacity Jabsco diaphragm pump instead, and have had no problems with it so far. I wired the pump directly to the batteries and use a circuit breaker to actuate the pump (currently taped to the head-to-tank hose. This means lifting the bunk covers to discharge the holding tank, but this must be done to open the valves anyway. 

For hoses, I used non-permeable West Marine hose for the straight run from the head to the holding tank, but beautiful Italian-made Raritan hose from the y-valve through to the hull discharge valve. I needed to make a 180 turn from the pump to hull discharge, which this high-quality (and expensive) hose can accomodate without collapsing. The Y-valve is made by Bosworth and works smoothly with no leaks. 

Yes, I cleaned out the hull grunge after the install

The most difficult problem was the seized 1.5" hull discharge valve. When the boat was hauled out for bottom paint (see previously), I removed and dismantled the valve. These valves are supposed to last a lifetime and are expensive. I found that the valve could not be made to work smoothly, so purchased and installed a new valve (note that the pictures show the old valve). I use freshwater from the bathroom sink for flushing the head, so don't use the seawater intake valve and hose, and left the original setup as it is, other than inspecting the valve and hose.

1.5" Marelon Ball Valve $210

 This setup overall works well for me. The new head is vastly more comfortable for me and my guests. I don't like using the Marina pump-out, but routinely sail in the ocean so can discharge the head tank beyond the 3-mile zone. It is now my go-to excuse for a sail out of the Golden Gate.

Costs:     

$30     Blue Sea A-Series Single Pole White Toggle 10A Circuit Breaker (West Marine)

$390   Jabsco 12v Diaphragm Waste Evacuation Pump (West Marine)

$210   Forespar 1.5" Marelon Ball Valve (West Marine)

$319   Jabsco Full-Size Twist'n'Lock Manual Toilet (West Marine)

$49     1.5” Bosworth Sea-lect® Diverter Valves (West Marine)

$73     1.5” Raritan Sani/Flex Sanitation Hose (Defender)

$22     1.5” Series 148 - White PVC Sanitation (West Marine)

$82     Tax (estimated)

$?       Tank vent hull fitting

$?       various hose clamps / other

$1175 Total (minimum)

Haul Out and Bottom Paint

I got the boat hauled at the Berkeley Marine Center last Summer to do a bottom job. 

All is revealed at the BMC

The bottom had not been painted for some time, and successive cleaning jobs had left the hull with no remaining antifouling action.

A filled blister

I sanded the entire bottom smooth and uncovered a couple of surface blisters. These were sanded out to solid glass and then filled with West Epoxy and 406 filler.

Dirty work

I cleaned and lightly sanded the prop and shaft before fitting new zincs and painting with Pettit Prop Coat Barnacle Barrier. I don't know how effective this product is - time will tell.

The water bearing was in great condition with no excess play. The prop-engine alignment was spot-on, and the prop shaft rotates smoothly with no slop.

Looking good

I rolled on two coats of Pettit Trinidad with an extra coat along the hull centerline, and on the keel, rudder and waterline.

While I was sanding and painting, I paid to have the BMC staff remove the blue Catalina top stripe and buff and wax the hull topsides.

Prop painted, hull with two coats of Pettit

The rudder got three coats

This short video shows the forward hull view.

Video showing aft hull view.

New shaft packing

I took the opportunity to replace the prop shaft packing using the fancy new HPME packing material. The new packing is a big improvement and seals the shaft with very little heat build up. I also replaced the raw water hull valve, and the large head tank hull valve (I will describe refurbishing the head and plumbing later).

Rear view

The topside buff and polish looks really good. I am not a fan of stripes, so like the look without the sheer stripe.

Costs:

$544    Haul and launch inc. pressure wash

$421    Remove Sheer stripe (labor)

$1300  Wax and buff inc. consumables and labor

$95      Sander rental

$720    Lay days in yard (9 days charged)

$158    Materials (e.g. Prop Coat, solvents, Festool sand paper, zincs, rollers, brushes, gloves, coveralls)

$36      Tax

$500    Pettit Trinidad HD 2 gallons

$3774 Total (minimum)

Cooling System Overhaul: Volvo MD2030D / Perkins M30

I sailed the boat home to San Francisco with my daughter, and noticed that the engine temp started to rise when the motor was driven over half throttle.  

Here is how it looked originally

And with the exhaust elbow and heat exchanger removed.

After stripping the water cooling system, I found that the exhaust elbow was almost completely blocked. The external paint was still good so there was no way to tell until the elbow was removed. The engine was installed new in 2004, so it was clear that the elbow had not been off for 20 years. This contradicts the standard wisdom that a nicely painted engine is a sign of good maintenance. It is actually the opposite - an engine with non-matching paint on all of the replaceable components shows that timely maintenance has been completed.

This is what the inside of the exhaust elbow looked like. The aperture was reduced to a hole about 1/2 inch wide by a build-up of exhaust soot. This mean't that there was enough water to cool the motor at low revs, but as soon as the revs increased and/or the engine load increased, the engine temperature started to climb.

You can see the new stainless manifold, exchanger boot, exhaust pipe and clamps in the above picture. Replacing these components was fiddly but not excessively difficult.

In addition to the elbow, I also dismantled and cleaned the heat exchanger, replaced the heat exchanger boots and hoses, replaced the freshwater engine water pump, and overhauled the salt-water pump.

The heat exchanger was cleaned by soaking in a weak muriatic acid solution.

I replaced all of the rubber boots and hoses to and from the heat exchanger, and used new hose clamps.

While I had the freshwater system apart I also put in a new freshwater pump, thermostat and fan belt. The old pump and thermostat had lots of gunk, but otherwise seemed to function fine.

Old freshwater pump and new pump.

I also, replaced the salt water water pump components. Parts4Engines in the UK has kits for all the pump components and gaskets.

I don't have a pic of the disassembled saltwater pump, but here it is prior

Also replaced the two fuel filers.

10 micron R24T primary with water trap and 

Perkins 10 micron secondary (final)

Last but not least, I changed the oil and filter. This is a tricky job as there is no way to drain oil from the sump without making a massive mess. I purchased a vacuum pump and tank from West Marine, and sucked the old oil out of the dipstick hole. This sounds really difficult, but it is not. I also used the vacuum pump to suck out all of the old antifreeze coolant from the engine jacket, as it is also hard to drain from the engine block. I replaced the oil filter (parts4engines) refilled the engine with clean oil and the correct (green) antifreeze. The last step was fitting a new K&N style air filter (parts4engines), and we were all done for this round of maintenance.

Sucking out old oil through the dipstick.

The engine now runs sweetly at no more than 90 celcius regardless of how hard the engine is pushing the boat. This was lots of work. I am now an academic, but my first career was as a tradesman marine fitter for the NZ navy, so I'm lucky to be able to do boat maintenance myself. I would hate to know what it would cost to pay a marine mechanic to do these jobs. 

Lots of new components, but not really shiny - shiny on the inside

Main Parts and Tool Costs:

$364 316 Stainless exhaust elbow (HDI Marine, also parts4engines)

$77   Trident Marine 200 Series Soft Wall Wet Exhaust Hose 1 7/8"Exhaust hose (Defender) 

$22   Trident Marine 720 Series T-Bolt Exhaust Hose Clamps 2.28" - 2.59" (Defender)

$28   Thermostat kit (parts4engines)

$120 Water pump (parts4engines)

$74   Heat exchanger end caps/boots

$14   Heat exchanger tank cap (parts4engines)

$3     Exhaust gasket (parts4engines)

$13   Fan belt (parts4engines)

$40   Raw water pump kit (parts4engines)

$60   Silicone coolant hose set (parts4engines)

$33   Air filter (parts4engines)

$26   Fuel filter primary (Amazon)

$7     Fuel filter secondary (parts4engines)

$8     Oil filter (parts4engines)

$130 Oil Change Vacuum Pump (West Marine)

        + various clips and hoses

$1019 Total (minimum)