@SipahSalar
What is the battlefield application of throwing sand in your face? Or tilting your boat, or lifting your boat? Or jogging through fake explosions?
What you have to remember about this particular sort of training is that it is a precursor to joining the Special Forces. The majority of the guys participating are already accomplished officers, ncos, and in special cases pvts/conscripts from the Infantry, Navy, and Air Force (SAR).
Now, the sand/mud in the face is part of the grueling physical exercises and tests that usually dominate the start of the course (Basic Underwater Demolition/SEAL) and culminates in Hell Week (a week of agonising physical training without sleep and with little food). This part of the course is meant to ensure that only those who are mentally and physically tough enough to become Special Forces progress in the course. While many drop out in this period, they will still be accomplished in their particular area or arms, for them they just weren't cut out to be SF and there's nothing wrong with that.
In terms of military application Special Forces will operate in areas where there is a lot of sand so getting covered in it in training while still being effective is good preparation (although something went wrong if you do get covered head to toe in sand while on ops). Tilting and resurfacing the boat in the water is an essential drill, you would be expected to do the same thing in combat if a RHIB or any boat overturned. Carrying the boat is part of the grueling physical exercises.
Running through fake explosions/fire with blank or live rounds going off in the background is meant to add realism to the training, that is the potential environment any soldier may be operating in. What you don't want is soldiers deployed on ops and then being phased or shocked when they are contacted by small arms or DF/IDF.
I used to have an Egyptian friend many years ago, he once showed me a video of an Egyptian parade where special forces guy eats a raw chicken after breaking its neck. I couldn't stop laughing, I mean that he could do that is awesome but what help will his chicken eating skills be in a battlefield? I wish i could find the video for you.
I know the video (there are plenty out there btw) and its ridiculous nature is very much intended for its particular purpose, a parade, a show/entertainment. However, it is an essential skill the SF guys have learnt. They may often deploy behind enemy lines or in enemy territory for long periods of time, and as such they have to be self sufficient in every aspect as logistical support may be hard if not impossible. Although they have their issued rations if that runs out they will need to learn to live and eat in the environment they are deployed in, that means catching/finding, cooking (if they can), and eating wild chickens (yes such a thing exists), snakes, birds, potatoes, vegetables, and any other form of food. Perhaps the most important skill they learn in this training which is literally called survival is how to find water.
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