with diving gear

with diving gear

Cutting yourself under deep waters?

I’m not exactly sure how to ask this question, but here it goes.

In the beginning of Tomb Raider 2, Lara cuts herself before leaving the submerged temple. Her diving equipment was destroyed so she couldn’t use them. So why did she cut herself? Does it have to do with the pressure underwater, since she couldn’t use her diving gear? A little later it shows her attracting a shark with blood from her wound..so was it for that reason?

If it has something to do with the pressure underwater, then I’d like to know why.

I’ve seen the movie. She cut herself to attract the shark for a ride out of Dodge fast. As for pressure under water, it doesn’t do a thing as to how fast someone bleeds or what colour. What does change the colour of blood at depth is the way that light from the surface has certain colours at certain depths or amount of water that light has to travel through filtered out and then reflect back to your eyeballs. Nothing to do with pressure, it has to do with how much water that surface light has to travel through. Red is the first colour that get’s washed out. Anything that’s red and is below 30 feet appears black to someone down there because that wavelength of light has been filtered out by the water column.
If you and the object were both at 30 feet depth or deeper and you used a hand held light on the object that had the colour spectra of the sun , you’d see it as red if it was less than 30 feet away from you. The amount of water between you and it is not enough to wash out the red wavelength. Further away and it will appear black.
So you see, it’s not actual pressure that affects light, it’s the amount of water that light travels through.