What is the Paper Boat?
The paper boat is a folded boat able to swim  for a while.
Obviously it is well known all over the world.
Folding a Paper Boat top
1

Take a sheet of paper of the size A4 (8 1/2" x 11"). Paper used for
ink jet printers will do.
Fold the upper half down on the red line.

2

Find the centre line by folding the left side on the right side and
by unfolding.

3

Fold downward both upper triangles on the red line.

4

It must look like this.

5

At the bottom fold the top strip upward on the red line.

6

Fold the two small triangles on the left and on the right backwards
to make them disappear.

7

It must look like this.

8

Turn the paper over and fold the other lower strip
upwards. You have formed the well known hat.

9

Turn the hat 90 degrees and open it. The thumbs must be inside. Lay
the upper and the lower parts on each other. 
10

It must look like this.

11

Fold the lower front triangle upwards on the red line.

12

It must look like this. .
. 
13

Turn the paper over and fold up the other lower triangle. You get a
hat without a brim.

14

Open the hat again and put the upper part on the lower one.

15

Pull the upper corners of the triangles in direction of the arrows...

16
Pull the upper corners of the triangles in direction of the arrows...

... as much as possible. Form the boat.
The paper boat is finished.
If using 8.5" x 11" ink jet paper the sail will be
visible above the sides of the boat.

17

Stretch the boat both to the right and left, and then separate it slightly
from underneath so it can float. 
The Boat With Three Sails
top
Perhaps it is unknown, that you can give the boat three "sails" in
the middle.

Don't make step 15. Fold the lower front triangle upwards on the red
line. Turn the paper over and repeat this folding.


It must look like this.


Turn the hat 90 degrees and open it. Lay the upper and the lower parts
on each other.


Pull the upper corners of the triangles in direction of the arrows.
Form the boat.

If the paper is not too thick, you even can repeat these steps and look
for more sails ;).
The Boat with a Big Sail top
Follow steps 1 to 10.

Fold the lower front triangle upwards on the red line and unfold. So
you find the centre of the square.


Fold the lower front triangle upwards on the red line. The tip should
touch the centre of the square.


It must look like this.
Turn the paper over and fold the lower front triangle upwards, too.

Make the steps 14, 15 und 16.
If the lower triangles are a little bit larger, the sail will be smaller.
Some Mathematics top
Shape

From the mathematical point of view the start for the boat is a shape
of two isosceles, rightangled triangles connected at the sides at the
right angle. You get the boat, if you reflect the lower parts of the two
triangles on the middle (red) line. 
Unfolded
... 
The boat has three parts, the front side, the reverse side and the
sail. The unfolded sheet (on the far left) shows these parts. The boat
has only a vertical symmetry axis. 
The Best Paper Size
...... 
If you use A4 paper and if you colour the outer walls of the boat red
and the inside walls pink and unfold the sheet, you'll get the results
on the left. The strips belonging to the inside walls are a bit too narrow.
It would be ideal, if the pink strips were the same height as the red ones.
This would work with the size 6:4=1.5. The sheet A4 has the size 1:1.4
(=1: [square root of 2]).
The net also shows all boats are equivalent.
Only the width of the paper and not the height influences the size of
the boat. 
Joke top
...... 
If you tear off the ends of the boat and the top of the sail and unfold
the rest, you get the shapes of a shirt  with sleeves or without. 
Gruesomely beautiful is the story to that: A boat is sinking. Weeks later
you only find the captain's shirt ...
Samayne Phillips from South Australia sent me the
Australian version, that she heard as a kid:
"Once upon a time there was a pirate boat that set off in search of
treasure, one day (as it neared an island) a storm blew up and the boat
crashed into some rocks (tear off the front of the boat), so the Capitan
decided to turn around and try to sail to shore that way (turn boat around).
Then they crashed into some more rocks (tear off the other end).
“No worries mate” (it was an Australian pirate) “we’ll just turn her over
and sail in upside down” (turn boat over). Then there was a huge
wave and more rocks and the top of the sail broke off (tear off top of
boat). Well after that there was no help for it, the ship sank.
The exhausted crew swam for the shore, but the Capitan went down with the
ship (‘coz that’s what captains do) and all they found of him was his shirt."
Paper Boats on the Internet
top
English
Clay Randall (Money Origami)
The Sailboat
Freaking News
Paper
Boat Pictures Gallery
Hans Bodlaender
Traditional
Origami: Boat
Ken Cupery (Ken's Paper Boat Page)
An Exercise in Paper Folding[Instructions
published in 1887(!)]
Recordholders (Peter Koppen)
The Paper
Ship Folding World Record
German
Holger Dambeck (Spiegel online)
Im
Papierschiff über den Kanal
Robert Bronsart (Universitaet Rostock  Fakultaet fuer Maschinenbau
und Schiffstechnik)
Internationaler Papierschiff Wettbewerb
Stefan Beyer
Das kleinste
Papierschiffchen der Welt
wdrmaus (Sachgeschichten)
Papierboot
References top
Joachim Schönherr: Wir falten und falzen, Leipzig 1990
Gail from Oregon Coast, thank you for supporting me in making
this website.
Feedback: Email address on my main page
This
page is also available in German
URL of
my Homepage:
http://www.mathematischebasteleien.de/
©
2001 Jürgen Köller
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