The most effective lure for bluekurper on artlure are curlytails, usually large or extra large in orange or white. I love spinners, but have caught very few blues on them. Way back when spinners use to be the nr1 lure for them, but the feeding patterns of most SA dam's blues have changed. Most blues tend too feed more on algea and plants these days and would occassionally go for an insect imitation and very rarely go for fry. Some dams spinners will still work well, but in general Curly tails seem to work better. In my life I have spend a lot of time fishing with spinners and have probably caught like 6 blues on spinners, while I have caught countless blues on curlies. If the dam has clear water and little fishing pressure I would have more faith in a spinner. Trick with the curlies is to have at least 30 cm length between your hook and your splitshot and try to go as light as possible with your weight, while still casting good distances. Also fish slow!!! My father is an expert in catching blues on curlies, catching 6-8 blues over 2kg a season and he has perfected this art. Good luck:fishn