Last week I saw a perfectly round rainbow around the sun I was in the Maldives at ground level Other websites apparently say this is not possible unless viewed from a plane or very high I know what I saw and I have photos I'm not going mad am I?
what you saw is not a rainbow in the conventional sense, ie the sun must be behind you. However no doubt you saw a phenomenon induced by spliting light into it's component colours.
During periods of extreme cold during winter here in the western U.S., Sun Dogs are often seen surrounding the sun. They are, of course, ice crystals but give the appearance of rainbows...
Why not have a look at the Atmospheric Optics site http://www.atoptics.co.uk/ ? You'll find your halo and a lot more besides there, along with explanations of how the various phenomena happen.