Confidence: It might be this.
Notes: Saw this dragonfly presumably ovipositing in standing water on our garden patio. So I presume its a female and I think it's probably a common hawker based on the yellow costa, but body colouration doesn't match with my reference book (Brooks). Am about to post another hawker from same area with very different colouration, but also suspect may be common hawker. Any assistance welcomed!