I’ve been chased for more info about the build of our boat, so apologies for being slow - here’s an update and photos from earlier in the year when we visited! (Also see Travels section post) Back in February the composite work was largely complete; the hulls had been post-cured and faired and the interior structure was about 90% done. The topsides are beautiful and quite curved, so represent a time-consuming element of the build process and we agreed, last year, for Julian to take moulds from the topsides of our boat in order to improve the time-efficiency of this part of future CM46 builds. This, of course, delayed our boat but I guess I have plenty of empathy with the whole productionising, scaling-up and boat-building process, so was a soft touch when he asked. Having been unable to visit South Africa until early this year due to travel restrictions, the timing of our trip actually proved perfect to give us a great feel for the boat, the layout and spaces above and below decks.  Have to say, we were blown away by the quality of the composite work and the overall look and feel of the boat. Aesthetics are subjective but we think the boat already looks AMAZING and will only get better when finished and fitted. The spaces feel plenty big enough – actually bigger than we’d expected or remembered from our original visit when we looked at the shell of 46 #1. Maybe some areas will appear to shrink a little after fit-out when tables, doors and other items are installed but we were very happy (and a little relieved) with the saloon and cockpit layout that we helped develop - especially as it's now the standard layout. It’s much easier to envisage it all when standing on the boat than it was locked-down in our home loft office, with a lap-top screen, paper, rule and calculator!  While at Current Marine we finalised many remaining details with Julian and the CM team – from deck layout elements such as exact helm seat and winch locations to suit our reach, right down to our planned usage of lockers and resulting desired internal shelf spacing, etc, etc. Our mates will be amused (but not surprised) to hear we specifically went to a liquor store to check the average height of a rum bottle.  The furniture is all foam cored composite, fully laminated into the hull before being faired and finally painted. It contributes to the structure, is super-light and won’t creak. Locker doors are also foam cored composite panels and they were away at the veneer specialist, being laminated with our chosen oak finish. The last couple of years have been a challenging and full-on period for Current Marine. In addition to the obstacles presented by Covid they have also literally worked around their factory being doubled in size to accommodate more boats in build. Construction was in the latter stages while we were there and, unexplainably gratifyingly, even…

One of the fundamental benefits we see from a cat is the ability to carry a capable, easily launched tender. For us, that means:  Tough rigid hull Big enough to carry up to 6 people Reasonably dry ride Able to plane and cover a few miles quickly The balancing factor is weight. We’d also like our tender to be:  Light enough to pull up a beach Light as possible to minimise effect on the mothership when in the davits   Aluminium hulled RIBs tend to be the most popular choice for multihull tenders but a more recent breed of carbon composite boats is gaining popularity, so we had a good look at some options. Here’s a comparison table:  Model Material Weight Payload 3D Tender – Ultralight 330 Aluminium / PVC or Hypalon 41kg 550kg Highfield – Ultralight 310 Aluminium / PVC or Hypalon 50kg 585kg Highfield – Ultralight 340 Aluminium / PVC or Hypalon 53kg 663kg AB – Lammina 10AL 319 Aluminium / Hypalon 53kg           OC 350 GRP – glass or carbon 54 / 44kg 448kg AST 340 GRP – glass & carbon 39kg 480kg I didn’t know the 3D Tender range but a mate who has a 3D recommended them. Their Ultralight 330 model gives the size and payload we need, yet it’s almost 20% lighter than the most comparable Highfield (which is admittedly wider but shorter, with a slightly higher payload). In fact, the 3D is only 2kg heavier than the lightest carbon tender and has a higher payload, tough hull (although the inflatable tubes are more vulnerable) and a relatively dry ride.  http://www.3dtender.com It’s also the lowest price of all the above options. I’m still wondering what the catch will be… but we’ve bought one (now called Derek in a nod to his stowage location) and it looks well made to me.  Derek doesn’t have a double, flat floor (maybe we’ll add a light composite floorboard to keep kit above any accumulated bilge water) but he does have a lockable bow locker which will be great for fuel, anchor and any other small stuff left aboard while ashore. We’ll fit fold-down transom wheels to make it easier to pull him up a hard beach. Our controversial decision is probably the tube material and I’m braced to be told I’ve been daft. We’ve gone for Valmorel PVC rather their Hypalon option because Hypalon seams have to be glued, whereas PVC seams can be welded. Word is that glued seams are often the first thing to fail. Valmorel PVC is reputed to be a big step forward from older PVCs – apparently it doesn’t go sticky and break down in the sun.  We’ve just made a tubes cover (for some reason known as dinghy “chaps” – why?!) and, to be honest, are rather proud.  A few years ago Amanda bought a Sailrite sewing machine, made an all over sun-protection cover for our Pogo, Rush and has recently been working down the size range but up the complexity scale. Chaps are…

In addition to the widely adopted electronic safety equipment, we’re planning to fit two less well known “ultimate safety” systems which, like a life raft, will probably never be needed. Each of them adds roughly 1% to the cost of the boat – not insignificant but, on the other hand, surely worth it if they add peace of mind in exceptional circumstances.  Sertec CMCE Lightning Strike Prevention Yes, I did mean prevention not protection! Read on…!! Electric storms are becoming both more frequent and more intense in susceptible regions which is bad news for all sailors and, in addition, catamarans are statistically more likely to be struck by lightning than monohulls. Amanda and I (OK, especially Amanda!!) really dislike electrical storms, particularly offshore. If we have interweb connection when storms are around Amanda instantly develops a morbid addiction to the BlitzortungLive app, which graphically shows lightning activity strike by strike in real time. Phones, iPads and VHF sets etc are stashed in the Faraday cage oven (one day we’ll forget and cook them after they’ve survived a storm) and any suggestion of going to the (carbon) mast to drop the mainsail can be quite unpopular… for days. So, I researched lightning protection systems and discovered a company called Sertec, in Paraguay, who have developed a lightning prevention system called CMCE. It has been used on airports, tall buildings and merchant ships for a number of years and, more recently, Sertec have developed smaller units suitable for yachts. My physics education went no further than A Level so please visit https://sertec.com.py/cmce/Brochure-CMCE-ENG-v5.pdf  for proper explanation and watch this video clip https://youtu.be/29WMElhJUqo - but here’s my attempt at a crude summary of how it works: Powerful charges build up within storm clouds Below the clouds an opposite charge builds up on the earth’s surface The cloud sends down “leaders” looking for routes to balance the load “Streamers” go up from the ground and when a leader finds a streamer, lightning strikes Streamers can be prevented (through de-ionisation) in the area protected by the CMCE  Preventing streamers prevents 99% of lightning strikes How cool is that?!! The CMCE is fitted to the top of the mast and requires a modest sized cable (because it only carries milliamps from the streamer) down to a ground plate. This is in marked contrast to lightning conductors which basically attract lightning and attempt to conduct the massive charge to ground without damage en-route…. Which is a tall order. I think a CMCE has to be worth it for the peace of mind and, of course, to avoid the risk of extensive logistical problems and major cruise interruption while getting lightning strike damage repaired. The system is most straightforward to fit during the build process and I believe CM will offer it as an option to all clients. It is also quite possible to retro-fit the system to most boats and, for example, UK based Falmouth Yacht Services now offer installations up to superyacht size.  There should be another benefit to fitting a CMCE system. Lightning strike…

Our goal is to keep the boat as simple as we can while nevertheless wanting full liveaboard comfort and autonomy! So that still creates a fairly long list of systems, but we do want to eliminate the need for:  Air con - through great ventilation, light hull and deck colours and heat reflecting film on windows Diesel generator – through plenty of solar, a hydrogenator and large lithium battery bank   Propane/butane gas – through all-electric cooking  Our key system choices: Operational: Nav electronics: B&G plotter- speed – depth – wind – AIS – Radar  Pilot: B&G software / Raymarine electric linear drive Comms: VHF – Satellite – Cell phone Electric winches x 2  Windlass Nav lights Domestic: Induction hob Combi microwave / convection oven  Fridge 1 – Drawer fridge – easy access to frequently used stuff – Isotherm INOX 130 Fridge/Freezer 2 – Top entry – most efficient for cold air retention – National Luna 110 Legacy Double Hot & cold pressurised fresh water – 40lt calorifier Electric toilets x 2 Watermaker - DC / energy recovery system - can be efficiency run direct from the batteries - Schenker Zen 50lt/hr Heating - Webasto diesel / electric  Washing machine – bulkhead mounted - weighs only 18kg – DaeWoo Mini  LED lighting 12v charging points & 240v sockets Portable waterproof speakers – JBL - driven by iPhone / iPad – eliminates need for built in sound system 12v DC + 240v AC supply Most of the CM’s electrical system will be by Victron, to ensure compatibility and facilitate back-up service/info as required.  The CM is well designed with all major electrical equipment fitted close to the middle of the boat near the domestic battery bank, avoiding long cable runs.  This makes a single 12v DC system practical. 12v is generally required for nav systems etc but many boats need to add a second, 24v, system as well due to long cable runs to high load equipment. 12v Service Batteries: 4 x Lithium 200Ah LiFePO4  12v Engine Start Batteries: 2 x 85Ah AGM Inverter/charger: 3000w to supply the AC equipment: Hob and combi microwave – a few smaller galley appliances – AC sockets for misc equipment We’ll have to balance use of appliances at any one time but the next inverter size up (5000w) would be significantly larger and heavier, so we think a bit of active management will be a worthwhile trade-off… and discipline us to be careful with consumption! Overcook it and the inverter will say No. Charging  Rush will have four battery charging systems, making good use of renewable options, maximising autonomy and providing a level of redundancy: Solar – 2000w of panels on the bimini/cabin top – see later Solar System post.  Hydrogenator – The Watt&Sea was one of our favourite bits of kit on the Pogo, ideally suited to fast cruising boats such as the Pogo and the CM because output increases rapidly as speed climbs over 7 knots (20amps@7knots – 44amps@10 knots). Admittedly the Pogo had lower consumption (small fridge etc) but it felt great to leave an anchorage, set…

The choice between twin diesels and hybrid electric (electric motors with diesel generator range extender) was our most difficult decision and it actually gave us one or two sleepless nights. Fundamentally, the CM46 is light, easily driven and able to sail most of the time, so overall fuel consumption by the standard, twin 30hp diesels will be pretty low.  But hybrid, or even full electric, systems are the talk of the town and of course appealing, in principle. And if they’d work on any boat, surely it would be on a light cat.  We wanted a hybrid system to work for us (all electric would definitely not give the range and battery charging required for our cruising) so built up a spec with one of the well-known electric propulsion brands:  Twin 13kW electric motors  15kVA diesel generator (generator output is the limiting factor to sustained speed under power – but higher output gensets are too large and heavy) 20kWh 48v Lithium propulsion battery bank, feeding a smaller 12v house bank Run time on batteries: About 2 hours depending on speed – circa 10 to 14 miles Max speed in short bursts: Approx. 6.5 to 7 knots (max speed with diesel engines: Circa 10 knots) Cruising speed (using generator to charge batteries): Circa 5 to 5.5 knots (cruising speed with diesel engines: Circa 7 knots) Diesel consumption at cruising speed using generator: Circa 3lt / hr (consumption by diesel engines: Circa 2lt / hr) Total system weight (with above battery capacity): Similar to the diesels  This is our summary of the pros and cons of the hybrid system: Pros: A “forward looking” solution  Short periods (about 2 hours) with zero diesel consumption and quiet motoring at approx. 5 knots Large propulsion battery bank which would also feed the house system at anchor  Two props providing regen under sail, meaning we wouldn’t need a separate hydrogenator Only one diesel engine (the generator) to service Cons: Added complexity – 48v motor system – 12v house system – generator - fast chargers etc Diesel generator required (in our view) for motoring range and for recharging batteries as solar / hydro will not always sufficient  Diesel consumption by the generator at 5.5 knots would (potentially) be higher than diesel engines  Propulsion props are less efficient for hydro regeneration than specific regen props, leading to lower charging rate Higher cost Uncertain reliability factor with younger technology   Our hearts said go for the hybrid and we very nearly did.  However… we became concerned that system complexity was rising. DC generators (able to directly charge the batteries) are larger and heavier than AC. Generator output defines the power / speed available for motoring (once the batteries are depleted after two hours) and the 15kVA minimum required meant we’d have to go for an AC unit, to retain the low, centralised weight by mounting it in place of one of the diesels. This would have required several fast chargers to convert the AC output to quick enough DC battery charging… in addition to…

Steering positions seem to be one of the most controversial aspects of cruising cats. Inboard, outboard, single, twin, high, low - they all have pros and cons and people have (very) strong views!  Until we sailed the Pogo, with max beam at the transom and wheels out near the sides, I hadn’t realised how good it would feel, on a cruising boat, to have a great view of the rig, waves and traffic (even though I’d taken it for granted on race-boats). Once you’ve experienced it, you wouldn’t want to lose it.  But... there will also be situations when a protected helm position would be a real benefit... so it's a difficult choice.  After sailing various boats we concluded that outboard helms with visibility were our priority and we’d accept the compromise on shelter, on the basis that the pilot does most of the work, especially offshore. Sheltered helm positions tend to have poor visibility (at least on one tack) and on one or two cats you can’t really see the headsail luff from the helm…   Twin Versa Helms The standard CM configuration has twin wheels (I think tillers are an option), outboard towards the aft end of the cockpit, so that ticked the visibility box - and it turned out we wouldn't have to compromise on shelter.  We’re fortunate to have been boat-searching a year or two after the versa style, hinging pedestals, were developed. CM are onto them and offer an upgrade. It gives the best combination of steering positions that we’ve seen on a cat. The pedestals hinge through about 90° and give both: Outboard high position: Great sailing view + unobstructed visibility when docking, without peering through salty glass Inboard low position: Sheltered under the bimini - even fully enclosed by canvas cockpit sides There is an added cost for these pedestals, but steering positions are so fundamental to sailing enjoyment, easier parking and comfort that we think it's hugely worthwhile. Helm Seats We usually like to stand, rather than sit, at the wheel when hand steering but comfortable configuration for both has to be an advantage. Our solution (at the outboard helm positions) are seats with bases that can hinge up against the backrest when not in use: Fold a seat down to sit within comfortable reach of the wheel – or fold it up to create more space for standing behind the wheel, with the frame giving a bum-rest if wanted.  When the wheels are inboard it will be possible to stand by the wheel or sit on the aft cockpit bench, although a back cushion may be needed to shorten the reach for sitting back. Line handling from the helm We tend to use the pilot when hoisting, reefing and furling etc, which seems easier and safer than veering around, juggling steering and line handling. Nevertheless, the CM’s deck layout will be set up so that lines and winches are close to the wheels for manoeuvres.  Instruments Twin versa helms do create challenges…

Saloon & Cockpit Our boat will be 46 #2. Boat #1, for a New Zealand owner, will mainly be used for racing and weekend cruising, so its saloon and cockpit layout are more open-plan than ideal for us.  That gave us the opportunity to work with CM on a layout that will be the standard design and certainly fits our wish list: Indoor / outdoor living space through saloon and cockpit Large galley with all-round visibility and connection to the cockpit conversation Forward facing nav station for comfortable night watches Excellent visibility standing or seated Three cabin, Owner’s layout The saloon is pretty wide so the layout maximises use of that, which compensates for its length being restricted by the rig aft / long bows design. That pushes the forward saloon bulkhead aft. It’s one of those design compromises we’re happy with – a trade off in volume for better handling and behaviour at sea. The overall saloon and cockpit space is almost 5.5m long, anyway. If that isn’t enough, we’ve lost the sailing plot! This is the sketch of the layout. CM CAD modelled it to optimally fit the boat. It prioritises galley space and stowage, which is up-there with heavier, fatter cats of this length. Likewise the nav station. The sofa and table have space to seat 6 comfortably (8 at a pinch) with a few folding director’s chairs. It will lower to create a watch berth. There’s plenty of sofa space around the cockpit for choice of view, several people with their feet up or for rum&coke o’clock gatherings! Here we are locked down again in the UK winter… Can’t wait. We’ll add a roll-down canvas cockpit enclosure, meaning the full bridge deck living space will be usable in most conditions, including underway with completely sheltered steering options (which I’ll cover separately). Owner’s port hull There’s a queen size bunk aft, sofa and folding desk amidships and a big dressing / bathroom forward. There’s space inboard of the shower for a wet-locker (draining into the shower sump) and… a washing machine. Amanda has fully won that argument – I, incorrectly, thought we may manage without… We'd been interested in the transverse bed under the bridge deck configuration of some cats, which add's bed space. But, the compromise, on this size boat, is that the bridge deck has to extend further forward, increasing weight and slamming. So, we’re happy with an aft bunk layout that also allows us to talk through a hatch if one is off watch in bed and the other in the cockpit. A quick “all OK?” and it’s possible to relax again without getting up.  Guest starboard hull With cabins forward and aft and a shared heads amidships. The forward cabin has a smart design with three set-up options - double bed, twin bunks or workshop and stowage. The flexibility is ideal to suit various combinations of visiting family or friends.  The guest bathroom is probably the greatest internal compromise. Floor area is restricted next to the daggerboard case, but…

Mast Current Marine offer three mast options: Fixed aluminium plus fixed or rotating carbon fibre. They build their carbon masts in-house, which is rare and undoubtedly explains why we detected quiet “encouragement” by Julian to make the right choice!  Nevertheless, we thought long and hard about this decision. The advantages of cleaner wind-flow over the mainsail and reduced pitching from less weight aloft are real... but do they justify the cost of a carbon mast? CM’s upgrade cost is a bit less than some brands, but it’s still significant in our terms. After much deliberation, we decided we would go for a rotating carbon mast – although maybe not for the reasons you’d expect. We chose this option mainly because it makes downwind reefing possible – and because the more efficient the rig, the smaller and more easily handled the sails can be. Factor in the reduction in pitching and a rotating carbon mast should make a noticeable difference to comfort and safety. That said, I think this is somewhere you could compromise and, with an alloy mast, this boat would still outperform most. Shrouds We’ve chosen Dynex Dux textile shrouds because they’re well under half the weight of stainless steel. In fact, if we’d chosen an alloy mast, I’d have opted for these shrouds anyway to gain a chunk of the weight saving without the full carbon spar cost. Reefing from the cockpit There's a significant downside to a rotating mast that we're going to tackle. Halyards and reefing lines have to be locked-off on the spars, which normally means going forward to reef. To overcome this downside, we’re going to use constrictors instead of clutches because they can be mounted on the spars with their tails and release lines led back to the cockpit for remote operation. CM have suggested reef hooks on the leech reefing lines because once the line is pulled down and they're "set" no other jamming is required - and they can also be remotely released. Reef hooks also largely eliminate the usual problem of line chafe. CM are keen to work on the remote reefing set-up to get the spar design, lead angles and deck blocks aligned correctly. If successful, we’ll have the best of both worlds – the ease of reefing downwind of a rotating mast and the ability to do it from the cockpit.  Boom Having chosen the carbon mast we decided on CM’s carbon Y boom to match. The boom lends itself to a custom fit-out to make our reefing line system work – and the stack-pack can neatly attach to the outer edges to widen it and collect the mainsail effectively.  Three headsails on furlers We've chosen this set-up because we reckon there are big advantages for our style of cruising. We’ll have a code sail, a Solent and a staysail - all able to be furled from the cockpit. They’ll facilitate a comfortable and safe configuration in building breeze (easy to change down) – and also help us maximise progress (easy to change back up).  Staysail I really don’t like…

The construction system was an aspect that drew us to CM. It uses top end materials, not generally available from production brands.  Epoxy resin, carbon and e-glass, PVC cored laminate is infused and post cured. The resin is the glue that bonds all the hull materials together so it has to be best to use the strongest glue. Epoxy resins have up to four times the bond strength of polyesters (used by most builders) and vinylester (a modified polyester) falls between the two.  From my experience, epoxy is essential if you want to build a light and strong boat. Race-boats wouldn’t use anything else (unless restricted by class rules, to limit cost).  Carbon fibre adds stiffness for a given weight but also adds cost. CM offer a couple of options regarding the amount of carbon used and we’ve opted for bulkheads, bridge deck and cabin top. They create a carbon “box” in the middle of the boat where the hulls are joined, the rig sits and shrouds attach, which should contribute max stiffness per precious £. The forward cross-beam and longeron will also be carbon wrapped. As a yacht engineer pointed out, stiffness is important in cats because their structure is fundamentally flawed! The mast sits on a bridge - the forestay is attached to another bridge – and the shrouds are attached to separate hulls, which could be on different waves. Monohulls and trimarans do have upsides... Stiffness maintains headstay tension (upwind rig efficiency), translates drive from the rig into boatspeed and reduces fatigue from flexing, to make the boat last longer. The hull and cabin top shapes are designed to keep the weight down, with simple curves in most areas allowing the use of un-scored foam. Complex curves require scored foam to bend to shape and these scores open up, fill with resin and add hundreds of kilos for no structural benefit.  Furniture The furniture in the CM is foam cored and laminated to the hull shell so it's light, it contributes to the overall structure and it can’t creak. Finish Like Gunboat and HH cats, the CM’s hull is finished by fairing and spraying. Awlgrip paint saves several hundred kilos over gelcoat. There are many colours to choose from and, after five years in the sun, painted epoxy boats tend to look much smarter than polyester gelcoated boats. AND... polishing is not needed! Now we’re talking!! Construction summary Coming from a composite boat production background, I’m impressed by the build system. Race-boat level lightness, stiffness and strength, with added benefits. 

After almost a year of research (I admitted we're boat nargs) we had a solid favourite boat, but to check our hearts weren’t over-ruling our heads we produced a detailed evaluation matrix spreadsheet with twelve criteria, each weighted relative to its importance to us – ie the most important were scored out of 20 - less important out of 10. Then we evaluated a shortlist of boats from the lightest and mid weight sectors. The matrix really highlighted what mattered to us and put each boat’s pros and cons into an overall perspective. A couple of boats offered amazing accommodation, but their performance would have frustrated us. One was a bit too skinny and just didn’t give the step up in space we’re after… although it was stunning to sail! I don’t think it would be helpful to post our matrix. The criteria and scores reflect our personal priorities and preferences – but if you’re choosing a boat and an analyser like me, I reckon it’s a great exercise to create your own.  Also, I don’t want to suggest that one boat is better than another – most have been well designed and built to suit the market they target. It’s just important to cut through the blurb, understand the compromises associated with each aspect of boat design, work out the features you'd like and how important they’ll be to you in the real world. Anyway, getting to the point, the boat we chose was the least well known – a CM46. The new CM brand has been developed by South African boatbuilder Julian Kneale of Current Marine, in conjunction with Schionning Designs who are well respected in the southern hemisphere although less well known in the north. The CM46 is built from higher spec materials than any of the other boats on our shortlist and that allows weight and performance-potential towards the fastest, but with more space. Crucially for us, competitive production costs in SA allow it to fit our budget.  http://www.currentmarine.co.za There will be pros and cons to working with what is a relatively small company. To be honest, having built the RS sailboat brand from scratch, I can’t help but identify with Julian and Current Marine’s aspirations and challenges. I think I prefer being part of that, over being smoothly processed within a bigger business. Hope that won’t prove too naive! CM only plan to build a few boats each year, so they won’t challenge the mainstream brand’s volumes and, right now, we’re happy to be getting our hands on one before lead times extend.