Great video!!!!! You explain your substantial knowledge, -(you spent 4 years building...)-, without pomp or ceremony... Felt like I was talking to a good-buddy, no posturing, just talking about something he knows something about... BTW; I wanna retire building a cat, which is no longer likely to be ‘glass.’

Excellent idea to weld the through holes in. Most of the ships sea chests I saw were welded in with replaceable valves on top. If the aluminum pipe showed signs of wear you could always hole saw it out and weld a new one in on the hard. I reckon Tim will like your idea as an option, regards Steve.

Thanks for all the info guys, appreciate it!

Great video as always guys. I was looking forward to this. Love your work. Thankyou.

Gotta respect Tim. He likes where he is in life and what he wants in a cat. He’s open to ideas, but after doing this for 30 years, he knows what works. He also likes his quiet life, and the size of his yard, and what needs to be in a performance/cruising cat. Looking forward to getting down there and getting started.

Thanks for posting this guys - was really interested in the bridge deck clearance of Jupiter👍

Thanks for taking the time to do this video. Always looking forward to are next meet on KZfaq .

Thanks for the video, very interesting and informative. Fair winds and following seas. 👍👍🐾

Love your videos, thank you for sharing!

Wonderful QaA, well done! Thanks a lot you 2.

Great looking boat! and you guy's are doing a great job with this channel, Fair Winds!!

Really good video, especially the electronics. Boat keeps looking better. Thanks

Thanks you answered multiple questions I have had about aluminium boats.

Wowzers. Lots of things to consider. Thanks for sharing your thoughts & build of your lovely vessel. Fair winds and safe travels.

Nice work Jamie & Princess, Great information & well presented

LOL, the 50 ft hulls were probably mine. Tim just had them completed and pulled out in the yard until we can get there to start on the bridge deck after travel returns to "normal".

She is incredibly light !! Excellent

Ovewr and over I came to see this boat. Jupiter is a very nice boat.

Great video, weight is the no 1 enemy of movement followed by hydrodynamic drag and aero dynamic drag. Drag is best understood as friction through water, hull below waterline, foils and propellers. Or air, mast, rigging, superstructure above the water line. Good design manages these variables cleverly. Bad design ignores or tries to hack them. Material choice ( fiberglass and it’s core material, Aluminium, or timber, think wharram .) Determines how it’s built and plays into what the designer can achieve. Then it’s details which play into these macro elements. Speed in the bank is a huge factor, how one uses it is great seamanship. You exhibited a great knowledge of it all, it was a pleasure to see and hear.

hello cordial greeting I was impressed with the performance of your Cat. and I understood the advantages of when there is no wind, you have helped me a lot to choose the boat that I want to build

I love your boat. I bet the waiting list is much longer now. Do you recommend being there and supervising the build?

That was super interesting Jupiter people. If I were to build an aluminum boat again (now mono, Reinke 13M) this design would be at the top of the list. Weight and sailing characteristics are amazing. I had also tried to find a solution to separate minus from hull and failed. But have no problem with it so far after 22 years in the water. Technically oriented episodes have my special attention, but your other posts are also worth seeing. Keep up the good work.

Thanks for the video!

Hi since you’re first video about your boat I’ve been looking at them

thanks for that!

Thank you Jamie, for a genuine appraisal, it gives a great summary for people looking at Ally for cruising cats, the boat looks amazing, and i fully agree with you, she was not hobby horsing, it was experiencing a shorter wave set, life is full of muppets.

Hi, great videos on these cats! I recall, around 5 years ago, seeing "Lava" in Brisbane/Redcliffe. Seeing a Mumby in the flesh, I was quite impressed.

Your a pilot? Wow I’m am too. I own a Bellanca 19-14-3. Now I want to sail.

Really good channel, I sailed a lot on a Stratus 12, similar water clearance, could pass under it in the dingy, Queensland made.

Great discussion 👍👍

Usual discussion. Thanks.

If and when the inner forstay is re-done to make it removable it might be easily stored next to the shrouds as the length would match up better than attachment to the mast. On electrical and safety you're top notch so I would encourage you to make story boards and explain floating earth electrical grounding and neutral wiring on an aluminum boat. Thanks for another excellent video.

The wiring in the ceiling, now you explained its in conduette is good . I think access to all cabling as in time And metal will get effected by the salt. Easy to replace amazing, its a shame all other manufacturers don't do this throughout the boat , especially on a cat when you want to get from Hull to Hull,

Your channel is the ONLY source of info for the boat! Sorry about peppering you with questions!

Thanks, very helpful.

Great vlog and since watching your channel like many other people I have been impressed with the Mumby design .. seems everyone has problems with switches as the cheapest design wins out .. I’d rather invest in robust and redundancy especially in a cruiser/live aboard .. keep the videos coming and fair winds while in the Caribbean .. from mid Georgia in the US ..

Thanks lots of information, technology, well done. Are you sure you're not a partner/sales professional. Really great presentation. An eye opener. Thanks to you both. Elle.

Very go, Thank you.

Congratulations ! 😀

Thank you

Great Video! You've answered alot of questions i had as well as well as good questions i didn't know i should of asked. Looking forward to the pros and cons of aluminum cat video and the video on the electrical wiring. I knew that galvanic corrosion happens when two different metals touch but didn't realized about the floating ground so i will have to research into that. Thank you.

Hi again Jupiter! What a nice story! Having seen most of your videos I'm very impressed by your skills and what you achieved… Once again congrats. Very impressed too by the quality of the job done by the boatyard who built Jupiter². A question about that: would they be able to build any other custom catamaran based on the plans of an architect or do they offer only the Mumby 48’ and 50’?

Great video. So informative. So many additional things to think about with an aluminum boat. Also, 400k is an absolute steal for a 48' performance cat. You sure can't find a used one for that either.

I love this

That is a never nice boat, and the price is pretty amazing. I really enjoy your channel, do you plan on doing a cruising budget video anytime soon? I would like to see the drawings for larger boats Tim has plans for.

good content just subscribed best of luck

Nice cat. Had actually found this design somewhere on the web 6, 7 years ago. And had forgotten about it. Thanks for bringing it back to my memory. In regards to Top speed, I think it is far more interesting for Cruisers to know, what had been your top milage per day and whats your average daily milage on a passage? For the technical part, whats the aluminium sheet thickness on your boat and are on the bow and stern thicker sheets used? Keep enjoying your sailing trip.

Plukky has a build of a Mumby design right now. He is having it built in Vietnam, his video's are up now on YT.

A big greeting, I congratulate you, excellent Catamaran.I would like to ask : if it is possible to see more dynamics in Your channel? like only one day of adventures under water ,explaining the scuba diving in detail. Another epic day, singing several songs, the wife is very talented, the vocalist and captain of the Air and Sea on the guitar, another day just technical or mechanical, perhaps making the story super interesting, in the story and the music in the background are the magic.Is the stage ready? the cameras are rolling... Go action , final cut! best wishes

Thank you great informative video looking forward to the next update. You just answered a whole lot of questions that I thought of previously but never asked you personally. 😄

Hello, nice simple boat,i like it just wandering the alimiun thikness used in the diferent part (bottom hull, top etc...) and the quality of the alumium thank you

Groovy man....

Aye m8’s, this is one of the best, most transparent, clarifying Q&A I've ever seen on KZfaq. Very good! And I'm impressed about Princess super professional acting through the whole vid, like a experienced news anchor. Thnx guys for sharing all this nutritious info! 🙏

I’m really surprised that your subscription count hasn’t risen sharply. Great crew and informative/ entertaining videos.

Very interesting to learn a lot. Plus, your moderator is cute as a button. Makes me want to get back to the Islands from Florida as soon as restrictions are gone! In the vid clip of the bouncing: My thought was how Galant the lady cut through the water. It is as if she is slicing the waves not pushing them out of the way.

I would love to have a Mumby 36' so I can solo it and take it into tight spots. I wonder if he would do a one off? Love your channel. Aloha~

Super boat, thanks for all your videos. Can you comment on any AC on board. I worry that the Aluminium with only 1 or 2 inches of closed cell/2 lb. foam (and) all the thermal bridges (aluminium ribs & gussets) it must get warm. And do you use any solar attenuation devices?

Good clarification on the wiring! After the previous videos it seemed like the wiring was just stuck up there with foam over it. My primary thought was "at least run it through conduit so it can be replaced if needed", so knowing that it is makes it all better. I've gone back and forth several times on whether I want to go aluminum or composite. Aluminum has some real advantages (including being completely recyclable and substantially cheaper for a one off custom build) and as long as the boat is big enough it can give composite a real run for its money weight-wise. But upkeep and repair-wise, I think composite wins. Anyone can patch a composite hull, even if it's ugly, as long as you give it a good surface, mix the resin right, and give it time to cure, you're left with a solid patch. Aluminum... well, I personally can't weld aluminum, and even among welders welding aluminum is somewhat a "specialized" skill. I forget which channel it was, but I just watched a video the other day where they couldn't find anyone that was even willing to weld aluminum for them. Even if I could weld aluminum, I'm not sure carrying a welder and having an inverter capable of powering said welder would be a wise weight investment, lol. But ultimately, I think this is one of those decisions that gets made for you most of the time. It's not like there are a ton of options out there for aluminum cats, so if you aren't a fan of those options, it means composite, unless you can spring for a custom design. Currently I am leaning heavily toward the Grainger Raku 48.

That's the boat Plucky wants and raves about isn't it mate?

I'm guessing the 45 and 50 ft versions would use the same hull width/shape, just change the length. Would they all have the same beam and bridge deck cabin?? Excellent video, BTW.

Nicely organized. I wish the build time wasn't so long and so far away.

Well, this would have been the video to see before I emailed you. Thanks for the reply!

Could future CAT built using glass???? How many times have you had done " bottom job" since you started sailing Jupiter???Saves all the worries n problems you mentioned.... mayb reinforced glass technology will improve in the future.... good luck n stay safe.... thanks for the enlightment n info....

Thanks for this guys! Small thing; what do you think about the practicalities of raising the dinette/settee area on a platform by some inches to allow easier vision when seated? I'm not too tall and I notice the windows seem to be a little above you guys when you are seated.

Good video. I'm very curious about your Mumby. (Hopefully I'm not too much of a busy body.) Your cabin walls: gelcoat on a waxed mold, etc.. is how sea kayaks are made. Good method. Here's what happens if there's ever a change needed or damage. I have a sea kayak that was hauled on to a dock while full of water. It folded right in half, huge holes busted out of the glass/kevlar hull/deck. You grind out the loose damaged material, feathering the hole. Then you trace an outline and cut a few layers of fiberglass each layer smaller than the one beneath it. (biggest on the bottom, smallest on top) Then on construction plastic (won't stick) you stack them up and apply epoxy. Easy. Put it over the hole smooth it out. Then a layer of epoxy with some lightweight fairing filler, sand it flat, color it - done. Gel coat can be reapplied and epoxy, vinylester, the fairing compound can all be sanded down through the grits and buffed out shiny as a mirror. You can brush on gelcoat and sand it, synthetic-steel wool, buff it to perfection. Fiberglass (GRP) on the inside of an aluminum boat is really a great way to build. You boat should last a hundred years. (The cheaper and older balsa core boats are basically temporary. I've built two cedar cored sea kayaks. One tiny hole or scratch or crack, water gets in and the epoxy won't fail, but it will pull off in large sheets taking a layer of the wood - which is the same thing. The only issue with running wires through conduit embedded in insulating foam is actually heat. There should be specs on this. It's against the (U.S.) Nat. Electric Code to run romex (plastic shielded wiring) or an extension cord through any kind of conduit because of heat. With LED lights being so efficient heat won't ever be an issue. If I had a suggestion to make I'd say look at all the boat cabins you can, find out where all the lights, fans( usually in the corners) are and then run the flexible conduit to all the possible spots with a piece of iron at the end - so it can be found with a magnet and then run all the conduit to where the electrical panel is and label the empty conduit. Then when you need to install a fan you already have conduit going to that spot. Snaking wire can be tricky but once you've seen someone who knows how to do it it's easy - even I learned. All the electric motor sailboats I've seen on KZfaq videos (and the Outremer 45 that was going to circumnavigate but turned around) have almost no range. Like sail to displacement ratios, there's no way to cover a boat in enough solar panels to effectively replace the performance and range of diesel engines - even for the minimal use of a sailboat. It can be done, there will just be days were you cannot go anywhere. However, the Mumby as a performance cat has the first criteria, being able to sail in light winds. One of those heavy 'cata-condo-marans' that have to turn on the engine in 6-7 knots winds won't get very far with electric motors. (This is from a happy Tesla owner - so my bias is for the electric motor.) And yep, this is also what I've learned as I search for a multi-hull: Most cats have pretty good cruising speeds, the real plus of a performance cat is being able to sail in lighter winds. re 'the plastic spacer.' This is like a dielectric coupling for connecting copper pipes to zinc galvanized pipes. I've got years of experience with this. First of all if you don't use a dielectric coupling (a plastic sleeve/seal separates the copper from the zinc) your galvanized pipes will rapidly corrode(rust) and leak. The house I live in the contractor put in a new copper waterline to the house, connected it directly to new galvanized pipes. Within three years the longest pipe in the house was rusted and leaking along its entire length. Other pipes were rusting too. I've never seen it this bad before. I replaced most of the piping with copper, used dielectric couplings at every connection - 12 years no problems. Plumbers have told me that eventually even with the couplings there will be a problem. I've never seen it. So I think with some care your boat should be fine. And on an aluminum hulled boat I'd prefer aluminum through holes welded to the hull with the plastic fittings inside the hull. I've seen too many plastic fittings on tanks, swimming pools and things get just a bit too much stress and snap off or crack. Position the right sized bungs and some kind of mallet next to all of them- but so they won't float away. Maybe also a chisel in case there's a piece of the plastic fitting sticking in the way. I'm sure there are boat people who know a lot more than I do.

This has been one of your better videos. Very positive

Really appreciate your channel Jamie, and love the design. I’m interested in the design plans to build one to cruise the east coast of Australia, how do I get into contact with Tim if you don’t mind?

Love your boat...has anyone told you..you look like Tom Jones 😄

If your using those corrugated flexible orange conduits from the Philippines it will be tough to replace those wires best to use the rigid orange pvc conduit pipes.

Thank you guys for the video. Very helpful. I haven’t heard back from Tim so assume he is completely swamped with Enquiries. It was very interesting to hear there is a 50ft version which may suit our needs better.

not sure if it's a common question or not but....what were the skie's like when you were young ?

Exellent Video Verry well presented and Informative , Your not related to the Folvarie"s are you , You look exactly the same as a Mate of mine LOL

Hi guys, we made our inner forestay and bridle out of 10 mm dynema and tension with a rigging screw I lash it to the backstay when not at sea to make tacking easier on the sail. Our through hulls are 25 mm round bar welded to the hull, and threaded with 3/4 plumbing dies with a 12mm hole drilled, leaving 5mm wall thickness at the thread. As for painting the bilges ask anyone who has an aluminium boat with painted bilges 20 yrs old, I have met dozens who regret ever letting paint near the bilge. The trick is no leaks, we sprayed lanolin ( lanox) as a precaution before launching 6 yrs ago. I still hose the bilges if we spill any salt water and keep a container under the shaft seals to catch the odd drip. Question did you make integral hull water tanks and if so did you paint inside? I did and it is starting to bubble up and flake , so we might resort to putting bladders in. Not ideal but if I built again I think I would use polypropylene tank/tanks on the bridge deck . Cheers Shayne Mumby Cyber Yes !

Awesome discussion! I'm studying catamaran design and learned that a fractional rig such as the Cyber will have a lot of weather helm when the rig COE (center of effort) is aft of the CLR (center of lateral resistance). Looking at Jupiter, the daggerboards look pretty well aligned with the mast so presumably the normal COE would be aft of the mast. Does Jupiter have excessive weather helm? And if so, do the rudders cause the boat to slow down while overcoming it? Sorry for the geek question but I'm trying to figure out a sail plan and autopilot requirement for a boat with the same sort of underwater profile as Jupiter.

I totally understand and recognize the quality and ability of the Mumby design and the capability of the materials it's made of. But since so few are being build, it's a rare duck, and then you mention Lagoon as being overweight and slow. Well, the Lagoon 45 will any day sail half windspeed, and do it in a very secure, comfortable way. Lagoons are mass produced and are therefore actually obtainable. They are somewhat pricey, but hold their value well, and are easy to sell on, if the owner so desire. I am not sure that's so easy with a boat produced in extremely small numbers, specifically customized to the first owner's needs and wants. One offs are more expensive to buy and harder to sell. One-offs demands a long waiting time from order to delivery, and in many cases doesn't have a very nice finish to them. To me a thoroughly tried and tested product gives me more confidence than the opposite. Just my 5 cents, because everyone seems to be picking on the Lagoon... 😉

Gj that was fun. How da heck did you manage to find a boat nobody knows exists?

Thanks a lot for that Jamie. I did get in touch with Mumby about 6 weeks ago, he answered that he was back building the boat. I then fired out a bunch of questions and still waiting for the answers...You have answered a few here. I find it very concerning if the yard is overwhelmed and you can't get a good communication with the builder all the way in the Philippines. A couple more questions that I wish I had answers for if you don't mind : What are the saloon windows made of? Can you fix, change, reseal them. How do you ventilate the saloon? (from the top hatches only ?) What reefing system do you have? What can be installed? What is the deal with the Philippines? Can you import parts tax free, or get the tax back when you leave? Can you stay in the Philippines after delivery for a few months to stay close to the base and iron out the problems? The Mumby design is truly great but a bit dated....especially when it comes to the cockpit and connection with the saloon. is there anyway to improve that? Would the 50 provide 2 more feet of cockpit space? Thanks so much for all the info. It is great that Mumby gets to sell his production. Catamaran demand is totally off the charts now. You did yours at the right time for the right price. Most of us will have to wait 5 years or more...There are amazing deals on monos...just kidding. Fair winds.

Hi Guys, I could easily restate all the quotes about great boat find, price and finish etc. So I won't, even though I just did - lol. I will say in the video quality and content area, I truly like what your doing and appreciate your style. It seems to me that one aspect of design that is lacking for cruising - live aboard vessels is dedicated space for solar. Most everyone appears to want it and it always ends up an after thought for placement and space. One other issue that popped up in an earlier video you did was condensation from the cold metal. I'm not sure how bad it gets??? But wondered if that was a design issue that could be addressed??? And finally I'll encourage you once again: Please do some back story vid's like where did you grow up and how did you get involved in flying - sailing and what type of work did you do before all of it? Then how about some romance???? How did you run into Princess? was it love at 1st sight?? Were you as cool as you appear now when you 1st approached her??? Or did you crash & burn on your 1st attempt?? See Jamie - there are lots of great stories to tell!!!! All the best, Jack

What about a gen set and AC. I am spoiled and I need AC at least in my sleeping cabin. The tropics can be very muggy when trying to sleep. I have used the sailing small water force gen sets on the stern to charge batteries without solar but is there or could there be a dedicated space for a small diesel gen set?

The interior or the boat is made from fiberglass panels. They are made on a flat surface about 4' x 8'. Much of the interior has been copied with patterns which speeds up the process of finishing the interior. However there is always the ability to customize various parts of the interior. The interior finish looks great but it is very labor intensive. Tim has spent years training his crew to do this work as quickly and with as high a quality as possible.

Great jobs guys, thank you! One vote for the "floating earth" episode.

You guys rock. Yeah first comment

Great info. Thank you. How can I finance this boat?

A 4 year build Ouch! So glad that you stuck it out You have a great boat and are living your best life.

I'm liking this boat design much more now that you've explained it. I'm still not sure what the difference in weight is between yours and a Schionning Arrow 1360 and if your boat is the same width and mast height as the Schionning Arrow 1360. Everything I talk about is focused around the Schionning Arrow 1360 because I saw a KZfaq video about it and the boat name is Duet. It's such a beautiful boat and has a curved front cross bar which gives it sex appeal. I also love the deck house design and the hard cover design over the transom helm position. Your boat has some of these great qualities and I'm basically looking for some comparisons because I can't afford a Schionning Arrow 1360 unless I start a KZfaq video channel like you :)

Hi guys , 2 questions , how do i go about getting in contact with Tim and what is the cost of your boat to build

Great honesty build testimony!

👍🏼

based chad

Inner removable forstay , if you had gone that route from the beginning? Would you to this question what different would you have said make the inner forestay permanent Because you have to attach the sail, lift by hand its not on a furler . I got the impression you have leak issues with the water system leaking ,

In event of a lightening strike, will the aluminum shell ack like a Faraday cage and protect you and inner components?

👍👍👍

Who did your hay rack on your boom?

How much does a mumby Cat 48 plan cost and where do you buy the plan from any link please?

At 3:57 you mention the light ship displacement being 6,100kg, but everywhere else that I find very sparse info on Mumby48 the light displacement is listed as 8,000-8,500kg, with max-load at 8,700. Am I missing something? I'm surprised because 6,100kg would put it 2,000-2,500kg lighter than some of the most advanced performance-cruisers like Gunboat48, TS5 made of carbon-fiber. Is dry weight really 6.100kg? Did you have it weighed?

'we got a lot of shit on this boat' Great video!

👍👍👍👍👍👍

I am planning to do it in Bangladesh.

hello, in which country are these catamarans produced?

Galvanic isolator??