Estuary trout.

Fished a wee estuary spot yesterday evening, place was alive with small baitfish and sandeels. There was no sign of activity until the sun started to go down and then there was an hour of constant activity from Sea Trout attacking the shoals. Tried every size and pattern of fly conceivable on both floating and intermediate, they didn't seem spooked as they continued to hammer the shoals while I cast into them. Thinking next time a surface lure to make my fly stand out among all the other baitfish, any thoughts anyone.

Maybe they were mullet?,but if they were trout a few Rogans gadgets would do the trick

Hi Paul
As you may well know, sea trout can be thee most fickle of fish to catch in the sea on the fly. Sometimes it's just damn near impossible.
I know where you are coming from, I have seen 'shoals' of seatrout ignore every fly in the box, well proven sea trout flies too ( a rogan's gadget is a great fly alright). They can be seen coming right up next to the fly and 'eye balling' it, they know it just isn't real pray and thy don't take it.
It's easier to catch them in a moving current but for still or slow moving water, I think that it comes to the stage where they just won't accept a fly pattern at all.
Maybe try fishing further into dark but the only option might be to switch to spinning or bait (live bait is probably best).. Unless you get a fly pattern that looks and acts EXACTLY like a sandeel!

Never seen so many baitfish across one area before, think my fly was also a needle in a haystack amongst all the livebait, that's why I was wondering would something on the surface making a bit of a disturbance possibly attract some attention.

the chances are that they saw your fly in amongst the rest of the shoal, I guess, as it would have been acting diffrently.
worth a try with the surface lure. would be interested to hear if it works for you