I would just buy another Regatta with the bracelet. They come up quite often on ebay. IMHO, the watch is not seen to be that collectable(as yet), so get one now before the price increase, if that ever happens. I recommend this solution as I think you will have a hard time finding a separate bracelet. And if you do, the PVD patina will probably not match up to the black color of your watch body, making for a funny combo with less value.

So save the new one, and enjoy beating up the current one after you put on a nice diver rubber strap perhaps.