New South Class range of catamaran CTVs from Ad Hoc Marine Designs

by Sue Allen in Vessels 04/02/2020 John Kecsmar

Ad Hoc Marine Designs Ltd (AHMD) has announced its new South Class range of catamaran CTVs. AHMD is mostly known for its world leading Typhoon Class of Swath CTVs. However, AHMD has designed more than 50 different types of catamarans over the past 30 years and is conducting significant amount of R&D into the hydrodynamics of these hull forms. However, despite its vast catamaran design database, AHMD has taken the view: why reinvent the wheel?

Unknown to many, AHMD worked closely with the original South Boats Ltd. on the Isle of Wight until 2012, assisting Clive Jeffry with the DNA naval architecture and structural design of the South Boats range of catamaran CTVs which included designing their now famous flexibly mounted deckhouse. So it seems only natural for AHMD and Clive Jeffery to team up again. Clive Jeffery heads up Due South Designs Ltd and has collaborated with AHMD where both see the need for a simple no nonsense catamaran CTVs with a well-proven provenance and pedigree which the company believes is missing from the current CTV market.

AHMD has designed its all-new South Class range of CTV catamarans with Due South Ltd. based upon their collective knowledge and over a decade of customer feedback into the original range of South Cats by Clive Jeffry at South Boats Ltd.  The 24m South Class is the first of these collaborations that is the essentially a MK II modernised update of the hugely successful original South Boats range of CTVs.

In his own words Clive Jeffery says “I’ve known John Kecsmar since we first met in the late 80s at FBM Marine where we worked very closely together. We both had an eye for quality and innovation, the principles also at FBM. When I left FBM and formed South Boats, I kept in close contact with John where both he and Nigel Warren assisted me on the technical and structural design aspects of my growing brand of designs at South Boats. We have always remained close friends and it seemed only natural to join forces together again to continue the close working relationship to create the mk II South Class of CTVs at AHMD”


The first-in-class South Class boat is expected to measure 24m in length, though the series is available in a range of lengths. Those boats in the UK Workboat Code range will span 15-24m in length and will carry up to 12 turbine technicians. South Class boats designed to HS-OSC Code specifications, meanwhile, will be able to accommodate up to 36 technicians aboard vessels sized up to and beyond 24m where the loadline length is no longer an issue when incorporating the HS-OSC Code. For lengths in excess of 24m loadline, a maximum number of 60 technicians is possible, as per the HSC-OSC Code.

The maximum capacity for boats in this class will be 45 tons, including a maximum 20 tons of cargo on a deck strengthened to 1.5 tons per m2. Speeds offered are in the region of 20-30 knots, depending on payload and configuration.


For more information on offshore wind farm service vessels, click here.

Copyright © 4C Offshore 2019

  • ISO 14001 173953 2015 AHSO GBR UKAS 2 | 4C Offshore
  • Achilles UVDB Supply Chain Community | 4C Offshore