More Sri Lankan Gulls/Terns and a wader (1 Viewer)

Sorry about this barrage of waders and gulls - trying to ID them they literally makes me dizzy! So.... Please help! Thanks
The A.B indicates the same bird, but with both upper wing/underwing showing. I am hoping that this will help with ID.
Thanks again.

Hello,

the Terns are Whiskered Terns imo. Please note strong bill, capped/bandana appearance of the black head-patch and dark rump and Marsh Tern jizz including a dark breast patch.

But nr. 3 is a White-winged Tern imo. White rump, head pattern and extensive dark feathers on the forewing seems good for this, despite heavy bill.

But better wait for members with experience from your area.
And I am in awe About the excellent comments about Plovers here on BF. Wow and thanks!

Thank you.