Saturday, February 27, 2016

Carbon Fiber Rudder Inspection


I am finishing up a two day inspection of two Gun Boat Rudders at the Hinckley Yard in Stuart, FL.
I used multiple forms of NDT; tap testing, thermal imaging and ultrasound (UT). For heating the rudders for the thermal imaging I used infrared lamps that are made for paint and resin curing. These lamps a great for this use, they heat evenly and slowly. 
It is very important not to rely on just one form of inspection. Using multiple inspection techniques is how you can see the "big picture". I start out with thermal imaging, which I then process in software. This allows me to locate the anomalies that I will be using tap testing and UT to confirm.
Often it is possible to use an iPad with the software to due the processing on the job site. This is a way I can confirm what I see in the camera is an anomaly and then use the camera's built in later pointer to mark the anomaly. 

This image is thermal blending. It is the blending of a digital image and an IR image.
The laminate is visible in this IR image.

The light grey lines are foam stringers inside of the rudder.

Using an Olympus Epoch 600 flaw detector to confirm any anomalies found using thermal imaging.

Wednesday, February 3, 2016

Inspecting Sailboat Rigging

In the January issue of the Boat US Marine Insurance Magazine I have written an article on how to inspect your rigging. I did this because a lot of us sailboat owners are in areas where it is difficult to locate a rigger to do inspections for us. We as sailboat owners need to be able to keep an eye on our rigging. You can read the article online at: Seaworthy

Here are some photos of what to keep an eye out for. 

Look closely for the cracks in the stainless steel.
Rust is often a sign of crevice corrosion. 

Tuesday, February 2, 2016

Inspecting Chainplates

In the latest issue of Professional Boatbuilder Magazine I have an article about inspecting chainplates on sailboats. I find while surveying sailboats chainplates are not always inspected. At least not inspected well. This is not only by the boat owner, but by the last marine surveyor and sometimes the rigger who have last inspected the boat. It is true that it is not always easy to inspect chainplates where they are hidden by the deck and/or interior cabinetry. Some cracks are visible above deck level, see photos. Signs of water intrusion are often visible below decks and even if the chainplate does not have signs of corrosion, this is still a reason to pull the chainplate for further inspection. Below are some photos of chainplate corrosion. In future blog post I will go into more detail on how to inspect for chainplate corrosion.

Not all cracks and corrosion are hidden.

This Hans Christen had been recently surveyed, without recommendation to replace the chainplates. Photo curtesy of Rigorous Rigging
In the photo below we can see there is wide spread stress crack and crevice corrosion.
Closeup view of crevice corrosion.

Monday, December 14, 2015


As my work continues to involve more thermal imaging and ultrasound inspections, I have started a new website to provide information on these services. 

The goal at NDT YACHT is to solve problems using non destructive testing while working with boat owners, builders, boatyards, and insurance companies.

Trawler Fest Rivera Beach, FL

Once again I am happy to announce I will be part of the boat buyer's program at Trawler Fest in Rivera Beach, FL.

I am looking forward to teaming up with yacht designer Stephen Seaton  on a seminar about buying and building custom yachts. We will cover what you will need to know about having a custom boat designed and built. We will also cover the purchasing of a used custom boat, most of which are one off built boats. We will mostly cover metal which is the most common in custom built trawler materials, but will also touch on wood and fiberglass.


On a recent trip to Trinidad for a survey I was pleasantly surprised with the services available for the boat owner there. This is not the Caribbean Island you might be used to. You will not find an island crowded with tourists or your typical anchorages. In Chaguaramas you will find an assortment of boat yards and chandleries. My survey was at Peake Yacht Services where I found the staff to be very helpful. This yard is capable of repairs on any type of yacht. If you find yourself in Trinidad make sure you hire Jesse James as your taxi driver. Jesse is a true friend to the cruiser and he and his drivers will take good care of you.

Peake Yacht Services

Saturday, September 5, 2015


I will be giving two talks at IBEX (International Boatbuilders' Exibition & Conference) this year. I get to discuss my two favorite boat building materials wood (yes wood), and aluminum. The first session (205) is on using Thermal Imaging in planning repairs to wood and wood composite boats. I will be addressing how Thermal Imaging is used in the survey process and then the repair process. PJ Rodgers, service manager of Huckins will be joining me to give insight on how repairs are performed based on the findings of Thermal Imaging.
 IR Image of a wood hull.

The second session (504) I will be teaming up with my father, boat builder Howdy Bailey, to discuss aluminum boat building. Some of the topics we will be covering are; frame assembly, plating, weld prep, and prepping the hull for paint. 
 Howdy Bailey built aluminum cutter.

Friday, September 4, 2015

TrawlerFest-Bay Bridge 2015

Once again I will be part of THE BOAT BUYERS SURVIVAL GUIDE at Trawler Fest-Bay Bridge. I really enjoyed  participating in the one at Trawler Fest Anacortes. I will also be teaming up with Yacht Designer Chuck Neville on the session: AN INTRODUCTION TO METAL BOATS

Sunday, August 23, 2015

Hurricane Katrina & Why We Should Always Be Prepared

It has been 10 years since hurricane Katrina hit the Gulf Coast. I was out there a few months after the storm to retrieve a Rhodes ketch I used to work on. We all have seen the devastating images of New Orleans. Less attention was given to the Mississippi Gulf Coast. I was not prepared for what I would see. Whole neighborhoods unlivable, casino barges high and dry on the other side of Highway 90, a fishing vessel sitting a couple of blocks from downtown Biloxi. Here are some of the photos I took from that trip. The last one is of us leaving out of the channel. It was like motoring through a ghost town. 

Let us not become complacent with the past years of slow hurricane seasons. Make sure you have a plan for your boat in place. Boat US has a information available to help with this task. You can get it here: Also check to see if your insurance policy has hurricane protection that covers some of the cost to haul your boat or move it to a safe harbor when a named storm is threatening. This can be helpful when the time comes to prepare your boat.

Monday, May 11, 2015

Trawler Fest 2015

I am happy to announce I will presenting with some great names in the marine industry and cruisers at this year's Trawler Fest in Anacortes, WA. If your in the area stop in and say HI.

Here are the presentations I will presenting in, and they are many more availble so please check them out here:




Monday, March 2, 2015

Interview With Yacht Designer Dudley Dix

My third interview for a series I am doing for the Metal Boat Quarterly was with Yacht Designer Dudley Dix. Dudley is based in Virginia Beach, Virginia. He is originally form Cape Town, South Africa. His designs reflect his experiences of sailing and racing along the coast of South Africa and offshore. They are beautiful and seaworthy. Even though the article was for the Metal Boat Quarterly, the questions were about all of his designs including his plywood designs. Also we discuss his experiences as a sailor and amateur boat builder. As an owner of a Dix designed boat and someone who has worked on building his designs, this was a real treat for me. Visit Dudley's Website at
Visit the Metal Boat Society at

Dudley racing on one of his Shearwater designs in the 2014 Great Chesapeake Schooner Race. The schooner won her class.

DB-Dudley, when did you get interested in boats and start sailing?

I sailed with my dad from before I can remember. He was a provincial champion in the Flying Dutchman class and my memories of sailing with him are of high speed, flying spray and lots of laughter. It is no wonder that I am also a speed-freak on a sailboat. We lived on the side of a lake and I sailed my own boat there from my early teens.

DB-You are known as a yacht designer. What some of our members might not know is that you are also an amateur boat builder. Would you tell us about the boats you have built?

I have built 3 big boats and a few small ones. I am a professional designer but an amateur boatbuilder, with all of the passion and peculiarities that go with that title. My first big boat was “Tai-Neam”, a van de Stadt design of 36ft. Next was “Concept Won”, a 34 to my CW975 design. Last was “Black Cat”, prototype of my Didi 38 design and forerunner of my range of designs for radius chine plywood boats.

Of the smaller ones, there are two stand-outs. First was a 15ft tortured plywood beach catamaran in the early 70’s and also the first boat that I designed. The other is the boat that I currently sail and the prototype of my Paper Jet design. This is a high-performance skiff that I sail single-handed on trapeze with main, jib and asymmetrical spinnaker. 

DB-Did building your first boat make you want to be a yacht designer? 

It was building the van de Stadt design that made me want to be a yacht designer. There were some modifications that I needed to the design and van de Stadt did the structural, rig and ballasting changes, while I did the accommodation and deck redesign. That got me interested, so I enrolled with Westlawn and got my diploma through them.

DB-What was your first design?

I never marketed the beach catamaran, so I guess that I shouldn’t count that one. The drawings were hardly more than sketches that only I could use. CW975 was the first complete design that I drew, while not yet half-way through my Westlawn studies. It was for the 1979 Cruising World Design Competition, which it won. At the time we were planning to go cruising on “Tai-Neam”. When I received news that the CW975 had won the design competition my wife told me that no self-respecting designer would own a boat designed by someone else, so “Tai-Neam” immediately went up for sale and I started to build “Concept Won”.

DB-What was your first metal boat design?

I had a friend who built the same van de Stadt design as me but unaltered. A few years later he was planning to build a steel boat to go cruising and I asked if I could design it. He turned me down and planned to build a design from a well-respected designer. A week after I won the design competition he commissioned the new design from me, for a 35ft cruiser that I named the Pratique 35. He later started a professional yard and eventually built over 20 steel boats from 30 to 60ft, all to my designs and most of them new designs that he had commissioned.

DB-How has building your own boats and sailing them influenced your design work?

I was heavily influenced by Ricus van de Stadt, who developed fast lightweight boats and was the pioneer for plywood sailboats. There were many of his boats sailing in South Africa. His standard of detail was very good for amateur builders and I styled my standard of detailing on what I saw on his drawings. Once I got into designing boats I followed my own ideas on hull styling, seakindly hull design, aesthetics etc and soon learned what works and what doesn’t. I sometimes found that I drew details that I thought would be good for others to build, then while building them myself I decided that they were too much effort and figured more efficient methods. In the process I moved away from complicated concepts and ended up at “elegant simplicity”.

How sailing my own boats influenced my design work is more a matter of where I sailed them than the fact that they were my designs. I grew up in Cape Town and that is where I did most of my sailing. Cape Town is known as the Cape of Good Hope but also as the Cape of Storms. Cruising circumnavigators regularly report that the worst winds and seas of their voyaging were experienced rounding the Cape of Good Hope. Sailors from there are well-known for heavy wind ability because we have to learn how to handle the conditions or miss out on much of the sailing. That knowledge and experience affects my designs more than anything else; seaworthiness is a prime factor in what I draw.

DB-You once told me, and I am paraphrasing here, "I suffer from seasickness and I design boats that I would be comfortable on." Could you explain what makes your designs comfortable offshore?

I sailed in the 1993 Cape to Rio Race on a Shearwater 39, a moderate displacement cruiser that is seakindly, quite beamy and very comfortable at sea. During that race I decided to design and build a boat of my own for the next race but it was going to be 50% of the displacement on similar waterline length, so would be a lively boat. Lively motion translates into discomfort in big seas so I had to be careful with hull shaping to make it comfortable. I used a much slimmer hull, shorter overhangs, unbalanced ends and concentrated the major weights in the middle. The result was a very comfortable and light boat that is also very quick.

I can’t claim comfort for all of my designs though. The box-rule boats like the Didi Mini and the Didi 950 are beamy and light, a combination that will produce a lively boat. They will not be as comfortably at sea as boats like the Didi 26 and Didi 38.

DB-Last year you experienced a capsize on a boat you built and designed for the Cape to Rio race. Your articles about this capsize have appeared in Professional Boatbuilder and Cruising World. This must be quite a learning experience for a yacht designer?

Yes, our capsize was a learning experience. Afterwards a few people said that they bet that I wished to have not been there. My response was that, aside from still being in the race to Rio de Janeiro for a good result, there was nowhere else in the world that I would have preferred to have been at that time. There can be few designers currently alive who have been inside a big boat as it is turned over by the forces of nature, to experience the feeling of being mixed up with equipment, cabin soles, stores etc like the flakes of colour inside a kaleidoscope. 

A designer is steered by his experiences on a boat. If I had spent my life sailing in ideal conditions then the boats that I would have drawn would have been very different from those that have grown out of my experiences sailing off the Cape of Good Hope. The experience of what extreme seas can do despite careful preparations is invaluable and will always be in my subconscious when drawing offshore boats in the future.

The experience ratified one of the cornerstones of my design philosophy for offshore boats and that is the need for a healthy stability curve, with high angle of vanishing stability and minimal negative stability if inverted. There are many boats that would not have come back upright if capsized in the way that we experienced or would have taken a long time to do so. We were upright again in well under 10 seconds, yet the boat took in enough water to kill most of the electrics and electronics and left a lot to pump out. Staying capsized for even a few minutes will introduce considerable risk of the boat sinking and some of the crew drowning.

I learned also that just because there is a big wave to turn the boat over there may not be another to turn it back again, so the boat has to be able to do this itself. We were capsized by waves piled on top of each other to form one monster peak that existed only for a few seconds right where we happened to be. After it passed we saw no others even half the height of that monster.

DB-The boat you capsized on was your first radius chine plywood design, a Didi 38. A boat named Black Cat, that just won the Governor’s Cup Race, a race from Simonstown, South Africa, to the South Atlantic Island of St Helena. This is very impressive for a boat and design that are 20 years old. Could you tell us about the design of Black Cat and what influenced you for the design?

All of the boats that I have built have been plywood and that material forms the core of my design range. 

My target when I designed the Didi 38 was to draw a boat that could be built by any amateur with moderate woodworking skills and at moderate cost. It had to be quick to build because I had only two years from start of build to be on the start line for a major trans-ocean race. I wanted it to look like a quality GRP boat, not an amateur-built project. It also needed to have sparkling performance because I don’t like to sail slowly and this was, after all, a race. “Black Cat” has proven that I met every one of those target points. She has always been very competitive and has won some big races in South Africa. Now she has been optimised to the IRC Rule, which has made her even more competitive than before.

The methods that I developed when designing “Black Cat” developed into my most popular design range, with boats from 15ft to 55ft.

DB-You have perfected the radius chine method of boat building (first developed by Ted Brewer) in metal and plywood. Explain why this is a good method for an amateur builder and even the professional.

I don’t believe that I have perfected radius chine boatbuilding, I have just gone about it in my own way. I don’t know who really started the radius chine concept. Certainly, Ted Brewer was one of the first, using a variable radius. Ricus van de Stadt was also working on radius chine methods for steel and plywood designs about the same time but with a tighter constant radius that we called a soft chine. Many others have followed those two innovators and we have each done it in our own way. I learned it through Grahame Shannon, who combined a large radius with developed hull surfaces. I have designed radius chine steel and aluminium boats using my own methods and a large constant radius from bow to stern. 

Whatever method each designer used he had to learn how to shape the rest of the hull to make it work. For the deeper hulls that are needed by metal designs my constant radius forms worked. I learned very fast that those shapes were not practical for the much shallower hulls of lightweight plywood boats. For those I had to use a tight radius in the forefoot and much larger radii further aft. This didn’t matter with plywood because the sections are bent to whatever shape is needed while they are being glued on, in two layers.

Radius chine methods are good for builders because they allow most of the hull to be skinned with flat sheets that fall naturally to the shapes needed. The remaining radiused sections are skinned with plates that, for metal boats, can be pre-formed by most general engineering firms. The result is not true round bilge but is near enough that most people can’t tell the difference.

DB-You have even used this method on two of your catamaran designs. Could you tell us about the designs?

As designers we develop designs as families that are generically similar. We develop one from another and they gradually morph into different boats. The DH550 catamaran hulls were directly developed from the Didi 26 monohull trailer-sailer hull. The method proved to be even better for the long and slim hulls of a catamaran than the more dumpy shapes of monohulls. The Dix 470 developed from the DH550.

DB-Walking around the Annapolis boat show it was hard to not notice how many builders are using hard chines. I have seen them on your new designs. Could you tell how and why hard chines are being used after so many years of being frowned on? 

Chines have been viewed for years as a sign of amateur building and looked down on by production builders, brokers and yachting journalists. A few years ago chines started to appear on box-rule racing boats as a way of creating a more powerful boat that still fitted into the measurement box, giving more speed and a more competitive boat. From there chines started to appear on new class racing boats as a means to promote planing and surfing when power-reaching. Now fashion has taken over and chines are being used on production GRP boats from major manufacturers.

This all happened after I had worked hard to remove the chines from amateur-built boats. I ignored it until I had potential customers asking me to introduce hard chines into my radius chine designs, bringing me full-circle. I did it first with the latest version of my Mini-Transat racer, the Didi Mini Mk3. This is a box-rule design, so it made sense. Since then I have introduced the Didi 950 with a similar hull shape, drawn to the Class 950 box rule. A client asked me to scale down the Didi Mini hull to 15ft, which produced the Didi Sport 15. That will form the start of a series of sportboat designs of similar shape. 

DB-One of your articles in your book, Shaped by Wind and Wave, is titled "Mindset and Goal Setting for Amateur Builders". What would you advise someone wanting to build their own boat?

To just get down and do it. I find that those who think about it too hard will probably never build that boat that they want, whether large or small. When I started building my first big boat, at the age of 25, my friends told me that I would never do it, that I had to wait until I had enough money to complete the project, as they were doing. Twenty years later I launched my third self-built boat and they had not yet started their first, nor will they ever do so.

DB-What knowledge do they need for building a metal boat of one of your designs?
Same question for plywood construction.

For a metal boat, that answer depends on whether they choose to build from steel or aluminium. Steel is a forgiving material to work with, particularly welding. One can start building a steel boat with no prior experience of working with the material, learn as you go and have a good strong boat after a few years, having also gained a bunch of skills along the way. If the choice is aluminium and they are inexperienced in working with it then I recommend that they get formal training at the local community college before they even start on the project. Incorrect preparation and/or welding procedures will destroy the value of the boat and potentially also render it dangerous due to structural problems.

A plywood boat is about the simplest boatbuilding project for most men to take on. Most are accustomed to working with wood and capable of reasonable quality. Traditional wood construction methods need good woodworking skills that will benefit from formal training but modern plywood methods combined with resorcinol or epoxy adhesives and epoxy coatings are pretty tolerant of skill level. I started building my first big boat with no experience of that type of construction and made a good job of it.

DB-Not only are your designs built by amateur builders, you have had boats built in metal and fiberglass by professional yards. What are some of the challenges and differences in designing for the amateur builder compared to the professional builder? 

Professional builders know most of the details that they will use in building a boat. They generally don’t require as much detail on the drawings as the amateur builders do. I still like to show as much detail as possible for two reasons. First, it shows more clearly what I want in the boat when there are different ways that a builder could do it. Second, it opens up the design to use by amateur builders as well. 

Professional builders also have more reference books to answer questions when needed. I recommend in the documents that are supplied with our designs that the builder buys some reference books pertaining to the method of construction, for guidance when needed. 

In the modern world of impatience and instant communications a new problem has developed. It used to be that a builder would ask a question by letter and could not expect an answer for 2-6 weeks, depending on the distance from the designer. Now the same person might ask 3 or 4 questions in one day by email. This has to be kept under control or correspondence smothers us. The builders must take responsibility for reading and absorbing the information in the paperwork provided to them and not just jump onto email to ask a question because that is the easiest thing for them to do. Answering each question takes time and decreases productive creative time for the designer.

DB-You got quite a bit of attention when you designed the training skiff Paper Jet.
What was your inspiration for the design?

I spent a few years in sailing administration in South Africa, at all levels from club through to Chairman of the National Council. A subject of concern to all was the ongoing loss of juniors from sailing, partially because of the old and boring class boats that are used for junior sailing and partially due to the cost of moving up from one class to a bigger and faster boat. At the time I thought that there must be a way to get around these problems with one boat. It took a few years for me to properly apply my mind to it and develop the Paper Jet design. This boat allows one hull to be used with a range of rig configurations, from a simple una rig through to a fully-powered skiff rig with trapeze and asymmetrical spinnaker. It is accomplished with a basic lower mast in combination with two different topmasts and other components to make a modular rig. This allows sailors of different levels of skill to sail the same boat just by swopping some components to power it up or down.

DB-In the Nov issue of Professional Boat Builder you have an article about your latest design the Didi 950. This continues your long line of fast cruisers and racers. Could you talk about some of your new designs?

The Didi 950 is a 31ft plywood boat designed to the Class 950 box rule. This rule is aimed at producing boats that are seaworthy and robust so that they will be suitable for use as fast cruisers as well as racing. I have been commissioned to draw a bigger sister, which will be about 37ft long. That will come onto the drawing board in the 2nd half of this year.

I am also working on a 32ft gaff cutter, the Cape Charles 32. This is a plywood lapstrake design based on the very successful Cape Cutter 19 and Cape Henry 21 designs. At 32ft it is a good size to be a comfortable coastal or trans-ocean cruiser. With the raised sheer and flush deck, it has very large interior volume.

And in metal boats, I am currently completing an aluminium version of the Shearwater 45. This is a very seaworthy and surprisingly fast cruiser. It has traditional image above the waterline but modern underbody with fin keel and spade rudder. The fibreglass version of this design won the Traditional Cruiser of the Year and overall Boat of the Year Awards in the Cruising World magazine BOTY Awards 2001. 
Dix 56 built by Howdy Bailey

Dix 64 built by Howdy Bailey

Saturday, February 21, 2015

Inspecting Marine Hoses

Do you know the condition of your marine hoses? The hoses on our boats live in an inhospitable location and are often forgotten about. Here is my method for inspecting the hoses. Inspect your hoses.

What is the most common marine deficiency on all boats, power and sail? The condition of or incorrect type of hose. Often times on surveying boats I find fuel hose and engine water hose from auto parts stores used on boats. Even the highest quality automotive hose does not hold up well in the marine environment. Automotive water hose is not reinforced like marine hose. It will develop wear spots and can easily crimp. But even good marine hose does not last forever. I find hoses that appear to be in good condition until I grab hold of the hose and bend it, at that time cracks are easier to see in the hose. Squeeze the hose, does it have any soft spots? On other hoses the cracks and wear are easy to see, some of the worst are AC intake hoses where I have bumped into them and had water squirt out. I have found thermal imaging to be helpful in inspecting exhaust hose. The soft worn areas will have a warmer thermal pattern in the image. I confirm the areas by pressing against the the hose after the engine or generator is no longer running. 
The use of Infrared Imaging (IR) is useful in finding worn spots in exhaust hose.

The white area indicates a section of worn hose.
We can see in this IR image a small worn spot in the center of this hose.

By using spot measurements we can indicate the rise of temperature in worn areas of this hose.

When was the last time you inspected your hoses? When I had my yacht management business, every 6 months I would crawl around the engine spaces and bilges inspecting hose clamps for tightness and corrosion. At the same time I would inspect as much of the hoses that were accessible. It is fairly easy to do by running your hands along the hose and using your eyes, giving the hose a bend, (after closing the thru-hull valve) looking for cracking.  A good place to check for wear is where the hose goes over a fitting. These create hard spots in the hose. Closely inspect for anywhere the hoses may rub on an area of the hull or other parts. When in doubt replace the hose. 
Visual inspection is used to spot cracks in this hose. If left alone this hose will start leaking.

The cracks on this hose are visible and by touching the hose I am able to confirm the hose is worn.
This hose is cracked where the hose is connected to the fitting. The use of two hose clamps is doing more harm than good.