EXTREME SURVIVOR Research Base frozen water section - Rise of the Tomb Raider

Hi guys! This is me showing the Research Base level on the frozen water section, where you have to kill all of the enemies standing on the ice above you. This is on the EXTREME SURVIVOR difficulty. I was having problems passing this section so as long as on YouTube is no video how to pass this section, here i am: Strategy: make sure you got some poison and explosive arrows ready. When the bad guys trow smoke bombs to you, you will find yourself diving in the water. Take down with (Y) the first guy standing above the ice, then imediatly jump at surface and prepare your poison and explosive arrows. Then shoot them to all the enemies while you take cover on the middle box as i show on the video. Hope this helps! Thanks!