Have a look at these Ray, absolutely brilliant, mine get a lot of use outside in all weathers, never leak,they are impossible to accidentally disconnect, little bit expensive but you will never need to replace once fitted.If the link does not work google oetiker swing couplings

hth

http://www.coastalhydraulics.net/technical-library/Oetiker%20Fittings/Oeitker%20Swing%20Coupling%20Training%20Binder.pdf