Another busy and productive week here at Naval Yachts with continued great progress on building the hull of our eXpedition Passage Maker XPM70-1 also known as mv Möbius.  Plus Christine and I went on two eXpeditions of our own this week and I’ll put that up in a separate post.  Work this week concentrated on putting the bottom row of hull plates, which in its upside down state right now means the plates at the very top,  These are all 12mm / 1/2” and 15mm / 5/8” thick plates so they take a bit more effort to wrestle into position and tack in place as you’ll see.  With this final set of plates now in position the beautiful slender and slippery shape of Miss Möbius is now clearly visible and Christine and I spent some time standing up on the scaffolding running down both sides to take in her sexy curves and imagine even more vividly how fabulous it is going to be to have this hull under us and slicing so efficiently through the seas of the world.  Oh the places we will go!!

You can also now see the aft prop tunnel and skeg keel taking shape as their framing is now mostly complete.  The tunnel and skeg surfaces will be plated in next week most likely but lets stop with the typing and get on with the pictures so Möbius can show off her curves to you.

IMG_20180806_132920The bow is now fully plated from top to bottom on both sides.

IMG_20180806_132931All the slots have been fill welded to the underlying stringers, the nose cone is fully welded in and all that remains is for the curved transition plate to come back from the plate benders and be welded into the open triangle you see here.

PGL sketch 35Here is a quick screen grab of the model to show you what this curved transition bow plate will look like when we’re done.


IMG_20180807_182434Working our way aft on the Starboard (right) side we pick up where we left off last week as the bottom/top row of plates are pulled in tight against the underlying framework

DJI_20180808_111124and tacked in place.

IMG_20180809_104136You can see how the 10mm x 100mm flat bars are tacked along the entire edge of the plate just below where the new plate butts up against it to ensure that the plate stays perfectly flat as the seam is welded up.

IMG_20180810_120736Here is a a nice angle looking towards the bow with the Starboard side bottom plating now all tacked in place.

IMG_20180810_120744Standing in the same spot on the scaffolding and turning 180 to look aft, this shot will give you a better idea of the finished hull shape and you can see the framework for the fin like skeg up on top.

Prop Tunnel SkegThis screen shot of the model shows how the green skeg holds and protects the blue prop shaft tube and how the hull makes the transition to the scooped out tunnel for the propeller and rudder.

IMG_20180810_121208Here you can see how the 25mm keel bar which runs the entire length of the hull, extends in this area to form the backbone of the skeg and the vertical 25mm frames show the carefully engineered foil shape of the skeg is formed.  This will soon be plated over with 15mm thick plates that have been wheeled to these complex curved shapes and will be slot welded to the vertical frames you see here.

IMG_20180806_133326Looking from the aft Port corner and with Uğur and Mehmet providing some scale you can see where the prop tube will welded into the middle of the skeg framework.  To keep everything perfectly aligned during the build you will notice how there are several vertical fingers spanning the space where the blue prop tube in the rendering sits.  These were purposely not cut by the CNC machine and will be cut out when the hull is finished and the prop tube is slid in place and welded.

IMG_20180806_155717Looking forward and straight down the center keel bar shows the curve of the prop tunnel

IMG_20180807_095921Looking forward along the Starboard side of the skeg framework you can see the remaining bottom plates stretching out in front patiently awaiting their turn to be fitted and tacked in place.

DJI_20180810_103952Zooming out a bit, this shot shows how the tunnel exits right at the very rear edge of the hull at the end of the swim platform.

Section on WLOne extremely important aspect of an eXtremely efficient through the water hull design is the shape of the hull on the waterline.  This is difficult to gauge when you are looking at the whole hull in these pictures so I made this quick section drawing to contrast the shape of the hull at the outer edge of the deck rub rails in blue and the profile in yellow on the WL.


Makes it very clear just how long and skinny, high Length to Beam ratio (78.2/13.7 = 5.7) Möbius will be and why I use words like slender, skinny and slippery to describe this kind of hull shape.  You can also see why we refer to this as “a sailor’s motorboat”.  eXtreme to be sure, all by design and all in be best of ways to match our equally eXtreme use case and personal preferences and provide us with the just right for us Goldilocks boat.

Your fast framed video summary of the week is below and thanks again for taking the time to join us on this adventure.  Please be sure to add your comments, questions and suggestions in the “Join the Discussion” section at the bottom here.  See you next week.