Don't forget to check the stream side spider webs to see what is hatching. I know a lot of people flip over rocks and check to see what is crawling around it the water and that is a very good way of checking for nymphs and crustaceans. Checking the webs is a great way to identify what has hatched and what is hatching if you can't get close enough to check the insect coming off the water. I've resorted to checking the spider webs first before swatting around at the bugs flying around, I've been to close to taking an early morning bath in some incredibly cold water. It's also an easy way to examine the insect up close by getting an accurate size and reference for the vise and if they start hatching again. Slow down and check your surroundings, it may help identify the next hatch.