Merriam-Webster lists all three of those as accepted pronunciations [0]; like many things in English, there is significant regional variation.<p>[0] <a href="http:&#x2F;&#x2F;www.merriam-webster.com&#x2F;dictionary&#x2F;quay" rel="nofollow">http:&#x2F;&#x2F;www.merriam-webster.com&#x2F;dictionary&#x2F;quay</a>