Very, very elusive American Bittern

I reached Carlton Marshes on Tuesday didn't see the bird at all. With 2 Swift seen plus Swallow and House Martin.on Wednesday 25th April, the American Bittern seen with Rob Wil and James Wr just after 5.30pm flew from the dyke and flew east for 5 seconds. It started to tip down with rain and I had to put my camera away. Of course 20 minutes later, I picked up the American Bittern really close, my closest view yet barely 20 metres away but only seen for 5 seconds! by the juncos before it had dived behind reeds and flew when the camera came out. 5 Avocets seen on the scrape. On Thursday at 7.30pm the American Bittern seen for 3 seconds when it swam across the dyke. Justin spotted an excellent Short- eared Owl flying over the main part of the reserve looking back towards the centre and 22 Whimbrel flying in. Also a fine Green Sandpiper flew east. On Saturday 28th April I arrived at 4.30pm and the AB flew out (seen for 3 seconds) and into the meadow, Rob Will rang and we went round the eastern section of Share Marsh as soon as we got there we heard the AB was showing in the meadow but when we got back I just couldn't see it. I next saw the bird at 7.30pm when it flew west back to the dyke. Great to see 7 Avocets on the scrape. A Hobby flew over the main part of the reserve the Scrape and disappeared over Peto's Marsh at 7.40pm 20 Whimbrel flew in, another 7 joined them. 2 Cuckoos heard too and Cetti's & 3 Grasshopper Warblers heard but not seen as we walked back. Total of viewing the AB 113 seconds, after 33 hours and 8 visits!