Mark Thomasson wrote:With a cantilevered boom there would be a hug improvement in control - and in setting the sail down-wind. 

I had seen Gary Hoyt's genoa boom which is similar to what you say and I did think adapting such a boom for down wind sail control but it does not solve the question of the height of the mast which is really too tall.

Moreover the Tilapia's rig is not really a Ljungstroem rig as the sail cannot be opened downwind so the question of insufficent sail area would not be solved either.

That's why I now think about a conversion to junk rig.

Claude

Ps . I did upload main characteristics and drawings of the Tilapia (in the illustrations folder of this technical forum) for those who may need them to answer question one : is the boat good for conversion to junk rig ?

Hi everybody,

I am a new member of JRA and I wish to convert my boat, a Tilapia 6.50, to junk rig.

I am french (so please excuse my poor english) and live in South Britanny.

I have always been interested in traditionnal riggings and boat design and, as an amateur, I did even design in late 90's a trailorable coastal sailer named "Egoist" whose free plans you may find on internet (including a junk rig version !). 

A few years ago I did buy this Tilapia as it was supposed to have many of the qualities I had put in the "Egoist design": shallow draft for beaching, easy sail control, easy reefing, easy masting and unmasting ...

The use of the boat proved quite different : the rotation of the mast for reefing is just inefficent,  supposed masting by a single person is just impossible, sail control downward the wind totally misses a boom or pole control.

What's more motoring without sail is just frigthening whenever you motor agains waves as the unstayed mast is so high (10 meters for a 6.50 m boat) and flexible that you just wonder when will it break and fall on you.

In fact it did brake once at deck level in the mast hole.

The very first goal of this conversion to junk rig  is to reduce mast length, the second is to have an easy reefing rigging as the righting momentum of the boat is not very high due to its shallow draft, the third is to increase its sail area for light winds as i am rather a summer sailor.

Present rigging of the Tilapia is a LJ rig and you may see it in this JRA site as a PDF file called "The poor's man Ljungstrom rig (by Arne Kverneland)".

The architect of Tilapia was once successful in france with a boat named "Serpentaire", a 6.50 m plywood boat which won the mini transatlantic race in the 70's. Nevertheless, if the carene of the Tilapia seems quite good, the rigging was designed by a person mostly involved in windsurf who missed, to my opinion, sailboat experiment.

I expect to get from this topic help from experienced JRA members about differents questions I have :

1 Is the boat convenient for a junk rig,

2 Is the mast suitable for such a rig,

3 Is the mast position to be changed

4 Is the junk sail I already did design satisfying

5 Is there any other question or problem I did miss

I shall appreciate any help from JRA members and will put online all informations needed by them in coming days.

Thanks in advance

Claude