Скачать с ютуб indoortanktest_0001.wmv в хорошем качестве

indoortanktest_0001.wmv

For thousands of years, sailors have believed they could not use the wind to sail directly against the wind. They believed the only way to go upwind was by approaching in zig-zags (known as tacking). They didn't realise that a simple windmill could give their ships the ability to go exactly where they wanted, even if the wind was unfavourable. This test illustrates how easy direct upwind "sailing" is, and not the marginal process that some people believe. Find out more on http://www.sailwings.net/windmill.html