Hints and Tips



Jeanneau Tonic 23+2 Special

New rudder, extended keel and sugar scoop installation


Every TONIC owner knows that the Tonic is a large boat inside, so why not make it larger outside?

Sifka was a fixed keel version, but to improve her handling and stability, both the rudder and keel were re-designed and improved. This also resulted in the incorporation of a new sugar scoop stern which increased both the overall and waterline length.


The sugar scoop extension was moulded in situ as can be seen in the photographs, by extending the hull lines. The rudder was designed by the Danish designer Lars Olsen known world-wide. He designed a lot of boats and rudders. This rudder was originally designed for a L-27 sailboat.


Tonic owners with lift keel versions might consider a twin rudder version that would allow easy upright beaching.

The standard keel has a weight of 450 kgs ballast ratio = 34%. Adding 180 kgs brings the ballast ratio up to 43%. An extra 12” draft on the keel was made of 5mm stainless steel, with lead inside. It is screwed on to the keel with 10 mm screws. Not to get in trouble I decided to use the same keel profile. The draught went from 110 cm to 140 cm, which is normal for a boat of this size.

What does it cost ? You can't make it without professional help! I was so lucky that my brother and friends could help me. I only paid for the materials, 1.000 Euro (1993) Made in a boatyard today, I think the price would be 3.000 - 5.000 euro ! The changes has made the boat a lot faster and the performance in waves is also improved.


Svend Aage Johannesen TONIC 23+2 1986 "SIFKA" Denmark