Minimum size for round the world

[longcours62]

Minimum size for round the world without refueling ?
Your ideas, monohull, catamarans ,prao other !?
Your proposition for best fuel efficiency .
In 1990 a collegue propose this currious 20 m boat to us :




IN 1993/4 an architecte propose this more conventional boat :




And you ,your ideas ?

[gonzo]

Can you use any fuel? How about sail or other forms of energy gathering?

[longcours62]

In fine we thinking sail boat is more expensive than motor boat.
But il will be difficult for me to explain in English !
For example the cost began at the conception of the sailing boat : pillars,chain plates,'strongest framing in the mast area, strongest framing for the keel, keel ,support for fit winches and all deck equipment,mast,rigging,sails,sheet, halyard etc it cost a lot !
Another energy ? if you are thinking solar ...until now Solar Planet is not a very good example !! Cost a lot for building and go slower than if she have a very small mast with small sail ...
A Japonaise try with "wawe energy",but wawes, sun or wind.May be if one day the solar pannels catch the entire spectre assocaited with light an perform batteries .
Alcyone was fitted with Magnus cylinders but also the result was not so good .
No when I ask for some ideas it is with classic engines ,but why not new ideas on the hull .
Because with 100 feet hull it is 'easy' to perform but for one under 20 m it still possible (for example the hull of our actual boat could be charged with 12 or 13 m3 off diesel ,for a total of 21 m3)
But it could be interesting to thinking a better hull shape for optimize the concept .
I don't know if I am clear ?