AGM 2020

The 56th Annual General Meeting of the AYRS will be held on Sunday 26th January 2020 at the Village Hall, Thorpe, Surrey, TW20 8TE, UK starting at or after 4.00 pm (after the all-day AYRS meeting).
more here /…

RSS Forum – latest posts

  • Monohulls • Hydrofoiling Europe-Dinghy
    Hydrofoiling Europe-Dinghy by Urde, Jesper and Karlsson, Simon An interesting paper by two students at Lund University, Sweden. Includes details of the foils used.SimonAbstractThe aim of this master thesis was to develop and build a prototype of separate hydrofoils compatible with a Europe-dinghy (A common, single sail, one-person dinghy), to be used as a proof […]
  • Power craft & engines • The Ship thats a Wing
    An interesting concept, the illustration doesn't give any thing away but the idea is that the hull shape generates useful aerodynamic lift when the engines generate a certain speed.the link is:- ... lso-a-wingStatistics: Posted by Fredthecharlie — Fri Dec 06, 2019 10:26 am
  • Gossip & other snippets • David Lewis / Cardinal Vertue / Rehu Moana / OSTAR 1960 & '64
    We have received the following request for help:Dear Sir or MadamI am a journalist in my day job but outside this I have written a biography of the NZ sailor David Lewis. I am looking for previously unpublished or little known photos and writings about his Cardinal Vertue and Rehu Moana. If you or your […]
  • News • Model Boats magazine December 2019
    This issue has an interesting article about foiling model multihulls; lots of excellent pictures, no real information about the designs.They look as though it could be a way of experimenting with foils minimising the logistics of cost, transport and crew.Statistics: Posted by Fredthecharlie — Mon Nov 25, 2019 5:43 pm
  • Instrumentation & Control • Re: Accuracy of GPS speed measurement
    I have come to the conclusion that, based on specifications from receiver manufacturers, GPS speed measurement is not sufficiently accurate for drag measurement by towing. I have considered a couple of alternatives:1) measurement of speed at a shore mounted winch that is doing the towing2) measurement of speed by timing between start and finish lines […]

Optimization of the length of a Surf-Ski Kayak

This project has been undertaken with the aim of finding a method by which the length of a surfski kayak can be optimised in terms or having least possible resistance. Surf ski kayaking is a highly competitive international discipline that takes place on open ocean, it differs from other forms of kayaking because of the lack of regulations regarding the length of the boats. An aim of this work was to determine if the boats on the market today are fully optimised in terms of having a length with least resistance. Through use of software that incorporates thin ship theory as well as skin friction data from ITTC ’57 it was possible to calculate the wave making and frictional resistances for a series of lengths of Wigley hull forms with constant displacement and beam. This allowed a total resistance to be calculated for each length which in turn leads to an apparent ‘optimum’ length. In terms of boats currently available, it appears from the results that they have indeed been optimised effectively however only for a small weight range of user. A conclusion of this work is that there may well be scope for manufacturers to produce boats better suited for other weight ranges of kayaker or paddler as they are more often known.

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Multihull Capsize Recovery

Multihulls can be light and fast but cruising ones must never capsize: They stay inverted.
Single hulled yachts can be self-righting and seaworthy, some large and small ones can survive storms and work to windward in gales but to be quick they need deep weighted keels and a wide hull. Built in buoyancy can avoid sinking but they are outperformed by multihulls.
Can a multihull be seaworthy? Could one work to windward in a gale or sail on when mid Atlantic breakers flatten her? What about an automatic system for capsize recovery? Could a multihull heave to in heavy weather and work slowly to windward like a Contessa? Probably not, but perhaps it could be as seaworthy as the offshore racing fleet.

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AYRS NWUK Local Group – Winter meeting – 10th December 2016

As is now the custom at our Winter Meeting, members arrived just after noon for a 12.30 pm start. There were seven members and four of their wives present. Three apologies from absence were received from Roy Anderson, Steve McKenna and Colin Weir. After a short introduction, a Buffet Lunch was served which was enjoyed by everyone (thanks Col). Amply fed and watered, the Ladies retired to the conservatory leaving the Gents in the lounge to have their ‘official’ meeting.

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