Sensa is built to the International 5 Meter rule:  

( L + √S - F - 0.5 B ) : 2 =   5.

L length;S sail area; F freeboard; B beam.

All Int. 5 Meter boats have this measurement in common, but no boat is the same.

Sensa is an early 5 Meter, no 11. There were over a hundred made in  Sweden alone. She is one of the longest boats in her class, but was  quickly surpassed by newer designs coming along in the 1940's.
She stopped racing and became a cabin cruiser. She changed hands 15 times before I got her and I have the names she changed into and  the  names of all previous owners. I have owned her longest and am the only  non Swede so far.
She was commissioned in 1936 by the KSSS, the Royal Swedish Sailing  Association, as a price draw for the 1937 AGM, along with 5 other  boats. There is a half model of her in the KSSS Clubhouse in Sandhamn.
She is made of Honduras Mahogany on oak ribs. Erik Nilsson designed  her, a private man, with several Square Meter Boats to his name and  only one other 5 Meter, S 18 Yrsa, same length, 9,55.

Out of the 100  boats there are 3 boats 5 cm longer than her. All the important Baltic 
designers have drawn 5 Meters, people like Knud Reimers; Tore Holm,  Arvid Laurin; etc.
Only once Sensa proudly won the BCYC Round the Island Race in the  Racing Boat Class in front of 6 and 8 Meters and 2 Clyde Linear 30's  (finishing transom first ). It was an extraordinary year 2007, the 
100th year of the Meter Rule and Sensa beat the reigning National  Champion of Sweden who came over to Cowes for the occasion. Not by  boat speed, nor pointing ability, but these guys had never sailed on 
tidal water. This was her sweet revenge to a more advanced design and  a much later sail number. Since the last years of the 20th Century she sports her original race configuration again, and her initial name, 
all brought back by the previous owner, slight changes remain.
When I met the great grandson of the first owner who came to Cowes in  2007 to celebrate the Meter Rule, crewing a modern 6 Meter, he told me  that all the boats in his family are called Sensa, even his own Laser. 
He did not however know the provenance of the name. We see that often  in Sweden, that a name goes with a family and when the boats are sold  on, the name has to change.

The 8 Meter Athena was first called Ilderin.

Int. 5 Meters are a more economical version of the 6 Meter Class, only  slightly shorter, not more then 3 foot, but half the displacement. The draft is restricted to 1.10 meter by Class Rule. A small rig set 
forward in the boat, a short boom; a high narrow main sail and a 200%  genoa. The helmsman sits behind the swing of the boom. I am afraid  that the teak deck I had put in, is very unoriginal, she might be the  only 5 M. with a teak deck! She is a simple and elegant craft and it  is a pleasure to sail her.

Photographs afloat: Kathy Mansfield

 

YACHT DESCRIPTION

 

Owner:	Cornelius van Rijckevorsel
Designer:	Eric Nilsson
Class:	Int 5. Metre Boat
Year Designed:	1936
Year Built:	1937
Builder:	Kungsors Betvarv Sweden
LOA:  9.55 m 31.33 ft LOD: 9.55 m 31.33 ft Beam: 1.89 m 6.2 ft Draft: 1.10 m 5.486 ft LWL: 5.98 m 19.62 ft
LOD/WL Ratio:	xxx
Displacement:	1.870 tonnes
Thames Measurement:	5.14
Hull Material:	Mahogany
Hull Construction:	Carvel
Hull Frames:	Steamed Oak & Steel
Rudder:	Keel Hung
Sail Material:	Dacron / Cotton
Deck & Superstructure:	xxx
Superstructure Profile:	xxx
Interior:	Stripped Race Boat
Steering:	Tiller
Transom:	Aft Sloping
Rig:	Bermudan fractional Sloop
Engine Make:	Dihatsu
Engine HP:	6hp
Engine Mounted:	Outboard
Propeller:	xxx
Propeller Blades:	xxx
Mast Material:	Spruce
Mast Configuration:	xxx spreaders
Keel Configuration:	fin
Keel Material:	Lead