It'll likely be 1/2 inch pipe thread. You can get a fitting that will screw in that has a barbed end on it that your hose slides on to. They might make them in a 90 degree elbow style.
The fun will be getting the old one out. When you do take it to the parts store to match up the size.
Kinda like this one.
http://greatlakesskipper.com/bayline...-elbow-fitting