We have now been on Oxalis Borealis for 7 months and we passed the 5000 nautical miles milestone just after our Atlantic crossing. We navigated Biscay Bay and the Atlantic coast of Europe, the Strait of Gibraltar, the Canary Islands, across the big pound to Martinique and we are slowly making our way north, currently in Antigua as I write this review.
In summary, I would venture to say that we love our boat even more now than we originally thought we would; it delivered everything we had hoped for, and probably more. Despite very variable conditions, up to 40 knots of wind and 4 to 6 meters waves, we never once felt insecure on our catamaran. As we initially considered bigger cats mostly for security and storage considerations, we can now confirm with certainty that 12 meters was the right decision for us as a liveaboard couple with long term cruising in mind.
Here are therefore per order of priority the main points that come to mind with over 5000 nautical miles under our belt.
Nautitech’s Aft Helms
Let’s start with what was for us the biggest potential bone of contention and the only element that we were still hesitant about when we made the final choice of our Nautitech: The helm position.
Taking into consideration that helm placement is a compromise on a catamaran wherever it is, our conclusion is that the advantages of the two helms at the stern of the boat far exceed the disadvantages. The helm position may be more intimidating than a flybridge at first, and would probably remain so if we were just chartering a boat for a week, but once you know your cat, I personally believe it is much more pleasant to have the real sailboat feeling that comes with it.
The advantages are numerous… You can actually feel the helm as it is cable driven to the rudders directly under your feet. Docking the boat is a charm as you gently bring the starboard corner right where you are standing towards the dock and manipulate the lines yourself if you need to. But ultimately, I think the biggest direct advantage is to be with your partner and guests right there on the same level; there is no separation between being at the helm and being part of a conversation around the table. The most significant indirect advantage is that the mainsail is much lower than other cruising catamarans, which provides a larger sail area, better access to the boom, and a lower center of gravity for the sail plan. The roof is a really good large and stable surface to work on the mainsail or in our case to exercise and do our yoga. The helm design is an integral part of Nautitech’s approach of building performance-oriented cruising catamaran. People we spoke to were often afraid of a lack of visibility, but I am happy to report that you do have very good 360 degrees visibility even when the sails are deployed as you can see right under the jib/gennaker, which would typically be right in your face from a fly or semi-fly bridge.
Isabelle and I love to be either together sitting side by side at one of the helm stations, or each at our own helm station looking at our respective set of instruments and smiling to each other from the other side of the boat…

The disadvantages do exist, and they center around protection from the elements and visibility when motoring. First and foremost, when docking, you do not really see the front port corner from the starboard helm (which is where the engine controls are, unless you install dual electrical engine controls). For us, it is a non-issue: We have bluetooth headsets (also called marriage savers…) and one of us is invariably at the bow reporting on distances and obstacles while the other is maneuvering. With the experience that we now have with our cat, it becomes the same feeling as parking a car: Although you do not see the bumpers from the drivers’ seat, it becomes second nature to parallel park without hitting the car in front or in the back… The boat is just a bit bigger and somebody is typically there right in front to confirm your intuition.

The other main disadvantage is getting wet. But then, when are we at the helm station when it rains? Other than the occasional bad luck of entering or leaving a port/anchorage when it is raining, we can generally avoid getting wet at the helm station. It actually feels secure and well protected from the sea, even at night. In any event, most night watches are done from the comfort of the nav station or from the cockpit table, and the same applies to squalls, unless you are maneuvering or, believe it or not, unless you want to be there because you enjoy it too much. What does also happen very occasionally is a particularly large wave hitting the boat just the right way to soak you up. All things that monohull sailors take for granted, but a lot of multihull sailors seem to expect to be helming from the comfort of a fully protected enclosure, sitting on top. When you see the catamarans at a boat show, it is easy to forget that from a fly or semi-fly bridge, the inside of the genoa is what you end up looking at when the sails are deployed. Conclusion: It is a question of personal preference, with pros and cons for both configurations, but keep in mind that the fear of the twin aft helm stations is greatly exaggerated, especially by salespeople who do not offer this option.

Reefing
Now this is the real question that is often forgotten… Reefing on the Nautitech Open 40, unlike most of the competition, is traditional. You have to be at the mast to take or release a reef, there is no way around it. Most times, it is pure fun and contributes to the feeling of actually being on a sailboat. But at night, in the middle of the Atlantic, as you turn into the waves and they are crashing through the trampoline, giving you a full body rinse as you are attached to the mast and trying to winch your second (or third) reef… I guarantee you it is an experience that you are unlikely to forget. I think back about it with fondness and the feeling of accomplishment. But I do understand that it may not be for everybody; and it does require a certain level of physicality. This, even more than the helm position, is the one that you have to think about before choosing an Open 40. One advantage to also factor in is that traditional reefs with a mast hook or a strap and reef lines secured at the boom are sturdier (and less likely to fail) than automatic single line reefs. Like everything else in a catamaran, each design choice is a compromise between many variables, the most significant being comfort, performance and security.
I would also report that when push comes to shove and you just want to take or release a quick reef when going downwind, it is possible to just center your mainsheet and proceed with reefing without turning into the wind (and the waves). It may not be as elegant, but the mainsail does slide on the mast well enough to do it and at night, and/or in large waves, when you do not exactly feel like visiting the waves, it does the trick. It is also very doable to reef solo, but it does involve the autopilot.
Nautitech and Neo Marine’s after sale support
We have been very happy with the support from both Nautitech and Neo Marine, before and after the sale. But like any new boat, ours came with a significant number of issues to correct, and most of them took a while to discover. Nothing major, but a bit surprising when your expectations are for a new catamaran to be in perfect sailing condition. From everything that we have heard, we still consider ourselves to be very lucky, and for two reasons: 1) Our problems where relatively minor compared to most stories that we have heard (from ALL catamaran brands) and 2) The after sales support of Neo Marine has been an absolute blessing. Sincerely, we initially under estimated the value of having a full Neo Marine service team to support us both in La Rochelle and in Martinique. When we heard of boats that are supposed to be ready for a given date in La Rochelle and owners are still there a month after scrambling to finish a solar installation or other post shipyard work, in comparison ours was ready when we set our foot on the boat, at the exact date that was agreed on more than 6 months before. This seems to be the exception rather than the rule. Also, when we arrived in Martinique, the Neo Marine team spent two weeks taking care of the boat, going through the extensive list that I had prepared for them. All of it, even some things that I expected to pay for, was covered under their after sales support plan. I certainly bought a few things (like a new anchor) and made sure all my business went to them, but frankly, I did not expect this level of support, especially with all the after-sales support stories going around. I therefore highly recommend Nautitech as a human sized company where you are not a just a hull number, and Neo Marine as a very professional organization to support you in a world where we hear of so many representatives not being very supportive once their commission is in the bank account.
Now I’m sure most would want to know what problems we encountered… Well, the disclaimer is that they are no more or no worse than what we have heard for other brands, but on the flip-side, they are typically problems that would be so easy to avoid during the manufacturing process that they can be infuriating. Our main issue were leaks: Leaking portholes, leaking engine compartment, leaks through some screws, etc. Then we had problems that are related to Nautitech’s subcontractors: Water pipes filling with air due to faulty water tank assembly (Can’t it be glued correctly the first time?), B&G autopilot disengaging (still a regular problem, after a lot of testing and replacing every physical part, seems to be a software issue), leaking pipes, bridle that was way too long, etc.
The moral of the story here is to verify that whoever sells you the boat are as good with after sales support as they are at selling. Otherwise, it will quickly cost you a lot of time, money and frustration.
Solar Panels and Lithium Batteries
There is no question that none of the production catamaran out there come with enough electricity generation and storage for liveaboards. None.
Our lithium installation, consisting of 5 Epsilor lithium batteries, totalling 7250 Wh of usable power, has been perfectly satisfying. I now consider it to be a minimum, and would have certainly added one more battery just for total peace of mind.

Our 1050 Watts of solar panels built as an extension to the roof has provided ample energy during the summer in Europe, but we would prefer slightly more with the shorter days of the Caribbean. The overall design of the panels as an extension from the back of the roof is actually surprisingly good looking, and it does provide additional shade in the cockpit and for the dinghy (as well as the paddle boards that we also store above the dinghy rack). 1050 watts is generally just around enough to refill the batteries every day (on sunny days), except when we have to produce large quantities of water. If we were turning off the freezer, which frankly we could do most of the time as there is not much in there ( except when we are successful with fishing), we would have enough power most days. A last note here is that our solar controllers are under-designed. We have one Victron 100/20 MPPT’s per 350 W panel (this is the correct way to design for both efficiency and redundancy: One controller per panel), we actually are limited to 20 Amps per panel when each is actually in theory capable of pushing almost 30 Amps (at 12 Volts) in perfect conditions. We are therefore not charging as much as we could when the sun is at its peak; It is the one and only thing that I am disappointed of in the choices that we made for Oxalis Borealis. As an electrical engineer, I accepted the Neo Marine reassurance on their design despite my analysis and my direct request to provide 30 Amps controllers, and I should have insisted.
As a side note, I would mention that nobody seems able to correctly set-up the battery monitor and solar panel controllers for lithium. The set-up in La Rochelle was wrong, then when we had the manufacturer’s representative reprogram everything in Martinique, it was still completely wrong. After some research, there are good references about it on the Victron web site and we are now, finally, sure of our settings and able to trust the battery percentage indicator at the nav station.
The fridge(s), freezer and watermaker account for the vast majority of power need. In the heat of the Caribbean, each fridge can consume up to 150 Ah per day (we have one fixed one and one portable one that we use when we have visitors or for long passages). Our 65 l/h watermaker drains 25 Amps, and we need an average of 1.5 to 2 hours of use per day (we use it every two or three days, ideally when we use the engine anyway to lift/drop the anchor). What drives the electrical needs of a modern boat is therefore largely dictated by the need for cold storage and fresh water.
For long passages, we need more power. The choice is in between using the engines for a few hours every day or having a complementary source of power. The options are more solar or an hydrogenator. A wind turbine may be a logical choice overall, but not a large contributor during trade wind passages.
In conclusion, for total peace of mind I would consider adding one more lithium battery and a couple additional solar panels on the roof, and maybe also a wind turbine to for cloudy days.
Update July 2020: Our fridge thermostat was broken when I wrote the review, and I did not know… So the compressor was working 24 hours a day. Since it has been repaired, we have enough power with the current installation for all our needs, including the freezer. We spent 2.5 months at anchorage during the confinement and did not have to start the engines a single time.

Performance
Nautitech is a performance-oriented cruising catamaran. What it means is that compared to the main cruising brands, you will notice a positive difference both in performance and the associated pleasure of actually feeling like you are on a sailboat, but less spacious accommodations. With six months aboard, I can report that it is exactly what you get. We have been sailing as we saw other cats motor sailing. With a bit of wind, we are comfortable close hauling at 35 degrees of the apparent wind, although we know that the boat gets really happy only past 50 degrees. This seems to be significantly better than what we have observed of other production catamarans. It comes at the cost of leaner hulls and a bit more draught… But the hulls are more than large enough for our needs.
Now we’ve had the pleasure of also sailing with real performance catamarans, namely an Outremer 4X, and the succinct but complete description of the result is that they literally trounced us. I wouldn’t want the living accommodation of an Outremer, I don’t especially like it, and you can’t really put any weight in it, but it was a moment of both awe and forced humility.
It is very difficult to provide blanket performance statements, as it varies a lot according to wind and sea conditions, but generally speaking I think it is safe to say that our cat seems to be more at ease in light winds and getting closer to the wind than the major cruising brands that pack more accommodation (and more weight) in a relatively small 12 meter platform. Stronger winds seem to be the great equalizer for most production catamarans of the same length, and longer cats definitely get better average speed on crossings.
The Open concept
The Nautitech 40 comes with a very large cockpit area, but proportionally smaller inside living areas. Our plan is to stay in warm places… And therefore, we have more than enough inside space. The resulting large cockpit and large trampoline is an everyday joy in the Caribbean. I almost got fooled at the boat shows thinking that we would need all this space inside, but for us, the layout of the Open 40 is perfect. I realized after buying the boat that although it looks relatively small compared to other cats next door when you are visiting boat shows, it is still a vast and comfortable everyday boat, larger than most. I write this from the comfort and stability of a protected anchorage in Les Saintes (Guadeloupe), perfectly still as I look at monohulls rocking left and right all around us. Our home is really comfortable.

Complementary sails
If you are going to sail in the trade winds, you need one or more good downwind sails. Importantly, you also need a good sail for light winds. There are many options out there, and a lot of very good products. In our case, what drove our choice was that we are two on board and we were looking to achieve both objectives with one sail. We wanted as much simplicity and versatility as we could.
We therefore chose a Code D from Delta Voile and we have been extremely happy with our choice. It is a furling sail, therefore easy to deploy, and on a catamaran, it can go from 60 to 180 degrees from the wind without any pole. In light winds, say 6 to 10 knots on a beam reach, it makes us sail comfortably at 4 to 7 knots when others are motoring. Downwind, we drop the mainsail and let the code D drive us forward. We used it for two weeks straight crossing the Atlantic (with no mainsail), and we may have abused it, keeping it up sometimes with true winds well above 20 knots, which typically we should not do. It has served us well, although the tack point gave up the day before arriving in Martinique, which was no surprise after all this abuse. Easy repair.
Having at least one sail for light wind and downwind seems an absolutely essential addition that makes a significant contribution to our level of happiness for long-term sailing.

Design Issues
From a catamaran design standpoint, there are only two issues that I can think of that are I categorize as design flaws.
The first is the size of the sink… It is small. My understanding is that it will be larger in upcoming Open 40’s.
The second and more fundamental issue is the placement of the thru hulls associated with the bilge pumps. Where they are situated (all four of them), they are banging into the waves when the conditions are rough. Sea water is sure to eventually find its way into the bilges. Not in quantity, but I like my bilges to be perfectly dry.

Other Options
There is little to review with regards to other options as they are based on personal choice, except maybe the rope cutters and good primary diesel filters that I do consider essential items for long term cruising. What I would mention is to take ample time to measure all the consequences of the various options that you choose. Some will have an effect on weight, electrical consumption, comfort, etc. Some will just be more complex systems to maintain that are likely to break at one point or the other. Do you really need a generator? Air conditioning? Our opinion at this point is that these are items made for the charter market. Do you need these beautiful teak floors? I was sure I did, until I talked to people who had teak or flexiteak: Gelcoat is not as nice looking as teak, but it is cooler, lighter and easier to maintain. Electrical freshwater toilets? Sure, but as a live-aboard what if there is no electricity or a lack of freshwater? So, one conventional toilet for redundancy seems important and we have also been a bit surprised at how much freshwater a toilet can consume when you are trying to preserve this important resource. After living on the boat for over half a year, if I had to choose one comfort option that I would not go without, it would have to be the indirect lighting, which we complemented with small warm tone portable light fixtures on the table and the counters. I quite simply love the warm feeling of our boat at night, it really feels like home.
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10 Comments
Great article ; thanks for sharing your experience !
We go from mono finally to cat and look for a the old 40 Nautitech which we will adjust over time a bit here and there; question of budgets.
ONE question = why did you not put your solars on the roof ? related to reefing ?
Fair winds,
Eric
Great article Martin. I very nearly bought an open 40 but ended up with a 46. Absolutely brilliant boats and couldn’t agree more about choice of dealer. Key Yachting in the UK have been fantastic. A quick question, do you run standard alternators and or regulators with your lithium system?
Best regards, Jon. (Spirit of Bliss)
Hi Jon, The standard alternators that came with the boat were (luckily) regulated. So after pushing 100% of their rated output for a few minutes, they slow down to approximately 80% and it seems to be keeping their temperature to an acceptable level.
Hi Eric,
Although it does leave the roof clear for working the sails and using it (we exercise there most mornings), the main reason was that we could not fit over 1000 watts of panels on the roof and even if we did, there would be shade from the sails underway (and even at anchor as people with panels on the roof move their boom through the day). It also leaves us the option to add a couple of additional panels on the roof if necessary. As an extension from the roof, they are also high enough to catch the sun at anchor in the trade winds relatively early in the day.
Fair winds,
Martin
Great write up. I’d be interested to know how you have set your reefing lines up at the mast. What’s your procedure from going from no. 1 to 2 for example. Do you have multiple snatch blocks?
A picture would be worth a thousand words, but I can’t reply to a comment with a picture! reef 1,2 and 3 as well as the outhaul are secured directly at the boom (they come back to the front inside the boom and come out close to the mast). One block is at the base of the mast to align the line to the winch, but you can also go directly from the boom to the mast winch when time is of the essence. I’ll try to add a picture to the post in a few minutes.
Thks, we recently delivered our 40 round to Barcelona. I found it pretty tough to switch the reefing lines through the block while smashing about in the Bay of Biscay. And we stripped our no 2 line by going directly to the mast winch…not a great angle. I was thinking about some ammends here to make it faster, a double on the Starboard side 1 and 2 and maybe another for 3 on the other side, wondering if you had any thoughts on that one, I follow you on IG if that helps with the photos ;), cheers
Ah, sorry I didn’t realize that you had an Open 40. Yes, our reef no 2 line also stripped. NeoMarine replaced it with a 12 mm line instead of 10 (as per of Nautitech’s support). And we know of another open 40 that the exact same thing happened. But yes, your idea about having a dedicated block for each line sounds like a winner! Especially as I have also partially destroyed the block provided by Nautitech and we will have to change it soon.
Hi Martin, really really great write up. Thanks, I wish it was available as I was making my decision to buy the Open 40 (@sailingduality) just to confirm most of the things I already suspected.
Mine is in charter in the BVI with Horizon and we get to her about 4 times a year. Other than the short delivery from Guadeloupe, we haven’t seen a lot of deep water or variable conditions. I’ve only reefed before leaving the anchorage and haven’t needed to while under sail. I tend to carry full sail up to around 25 apparent since I know we are in protected waters. Gideon and I have discussed reefing as well.
My question to you guys is what’s the problems with the blocks and why would you need two working. Can’t you release the clew line when going from 1 to 2 or use the jammers at the forward end of the boom?
I could see the snatch block not big sufficient when needing the reef under load.
Thanks for confirming and walking through reefing downwind, I think I will try this next before when I really need to do it.
I haven’t added solar to mine yet, but am thinking about it. More details on your setup would be really interesting to hear. I’m going to pour over as many photos as I can find now 🙂
And when you say trounced, how bad are we talking? Agreed that the higher wind speeds are equalizers, but having said that I just out sailed a Saba 50 in 20-25 kts.
We didn’t do the fake teak and are pretty pleased with the choice. I did go for the dual engine controls, but it was highly recommended by Horizon and I wasn’t fully on board. I’m not sure if would do it again given the expense. Docking to port would be a struggle without it, but that’s the only case I can think of.
I wonder if there are any open 40 owners out there that aren’t happy with their choice.
Thanks
Gareth
Hi Gareth, sorry it took so long, we had very little connectivity for a very long time now.
For reefing… The double or triple block at the base of the mast instead of a single one would just be nice as going from reef one to two and exceptionally to three generally happens when the conditions are really unpleasant, at which point any operation saved feels fantastic. But certainly not a must have, more of something you would wish for at night in the middle of the Atlantic.
Reefing from downwind: Quite easy… Center the traveller, mainsheet as short as it’s going to go, 180 degrees from the wind and take a reef… It’s just harder as if there is any wind into the sail it may not come down without some significant help.
We should be in the BVI next week depending on the status with COVID 19.
Martin