This article follows Transverse Stability, Part 3: Dynamic Stability Part 3 of this series dealt with changes in transverse stability taking place once a vessel starts travelling through the water. This article discusses the way the stability of sailing yachts can be challenged at sea as a result of wave action. Wave action doesn’t reduce […]

This German translation of the original article in English was very kindly provided by Burkhard Hermes in October 2021 to facilitate access to the content for German-speaking readers and we are pleased to publish it here. Diese deutsche Übersetzung des englischen Originalartikels wurde uns freundlicherweise von Burkhard Hermes im Oktober 2021 zur Verfügung gestellt. Sie […]

This article is part of a series dealing with building best-in-class lithium battery systems from bare cells, primarily for marine use, but a lot of this material finds relevance for low-voltage off-grid systems as well. Lithium iron phosphate (LiFePO4) battery banks are quite different from lead-acid batteries and this is most apparent when it comes to […]

In this article, we have a look at the Volvo Penta MDI electronic black box while relocating it off the side of a Volvo Penta D2-40B engine in order to protect it from the heat and vibrations. IF YOU OWN A FAILED MDI BOX, PLEASE CONSIDER SENDING US PHOTOS OF THE INSIDE AFTER LIFTING THE […]

In July, I wrote about my experience with a homebrew twin-transducer ultrasonic antifouling system over 3 1/2 years on the aluminium sloop Nordkyn. It didn’t keep the hull clean once the antifouling reached past its prime, but the results were nevertheless very valuable as the system eradicated hard growth like barnacles on the hull, even in the […]

Starting Point I had hauled out the sloop Nordkyn for its less-than-annual bottom paint job. It was November, that year had been long, and so was getting the thin stringy weed clinging to the hull. In this condition, the boat is unusable. I was determined to make the effort last and so I generously sprayed […]

This article is part of a series dealing with building best-in-class lithium battery systems from bare cells, primarily for marine use, but a lot of this material finds relevance for low-voltage off-grid systems as well. This article discusses the protection of lithium battery banks in the context of marine installations. A previous article detailed the design […]

This article is part of a series dealing with building best-in-class lithium battery systems from bare cells, primarily for marine use, but a lot of this material finds relevance for low-voltage off-grid systems as well. Integrating a lithium battery bank on board a vessel introduces a few additional constraints and challenges that don’t exist with lead-acid […]

This article is part of a series dealing with building best-in-class lithium battery systems from bare cells, primarily for marine use, but a lot of this material finds relevance for low-voltage off-grid systems as well. Here, we detail the hands-on process of building a lithium battery bank from individual single prismatic cells. There is more to […]

This article is part of a series dealing with building best-in-class lithium battery systems from bare cells, primarily for marine use, but a lot of this material finds relevance for low-voltage off-grid systems as well. Batteries are about voltage, current and capacity first and foremost. This article discusses the performance characteristics of lithium iron phosphate cells […]

This article is part of a series dealing with building best-in-class lithium battery systems from bare cells, primarily for marine use, but a lot of this material finds relevance for low-voltage off-grid systems as well. Hundreds, if not more, of research papers have been published about lithium batteries, as well as numerous books. Still, a lot […]

This article is part of a series dealing with building best-in-class lithium battery systems from bare cells, primarily for marine use, but a lot of this material finds relevance for low-voltage off-grid systems as well. The development and mass-manufacturing in recent years of large-size lithium-ion battery cells for electric vehicles and grid-tied electricity storage has made […]

This article is a follow-up from Heavy Weather Dynamics: Yachts in Following Seas published some months ago. It has since become one the most read items on this site. While the original article applied to most sea-going monohulls, the following discusses more specifically fast modern hulls, or yachts in very fast following seas, such as can […]

With tropical cruising becoming increasingly popular and accessible in the last 2-3 decades, trends have developed in outfitting yachts for ocean cruising. Some of these trends that originated from sailing in moderate settled weather areas have resulted in significantly increased risks when a vessel is caught in severe conditions. Many of today’s cruising yachts, whether […]

AIS, for Automated Identification System, is probably the most remarkable safety improvement in decades for small craft offshore. The little project presented here involved designing and building a simple, very low power alarm system to keep an AIS watch at sea. Collision Avoidance at Sea Avoiding undesirable encounters with ships in mid-ocean has always been a […]

This article deals with some of the physics involved when a yacht is running before the sea, especially in heavy weather when waves are long and their front faces become steep. Yachts running in heavy weather and following seas face challenges that are very dependent on the characteristics of the design; the ability of the crew […]

One of the largest technological differences between fitting out the sloop Yarra in the early 1990s and launching the Nordkyn design in 2010 was the transition from halogen to LED lighting. The performance and quality of LED lights was evolving so rapidly that I literally deferred purchasing light fittings until the last moment.The following sums […]

There are lots of LED light fittings out on the market within a very broad price range. One can readily distinguish two classes of LED lights: Current regulated: those light fittings usually accept a wide range of supply voltages. Unregulated: the light must be operated close to a nominal voltage only. In order to operate […]

Significant damage sustained by sea-going vessels mostly originates from wave action. In this context, discussing the characteristics and behaviour of waves is valuable. Wave theory is quite extensive and complex, but only a very small amount of knowledge about waves is essential to small-craft sailors to anticipate the risks that can arise from waves. Waves […]

The Presto design was developed by Commodore Munroe in the 1880s on the US Atlantic Coast. The boats sailed up and down the coast some distance offshore and were confronted by the frontal weather systems and the influence of the Gulf Stream found in that part of the world. The first time I came across […]