The Mariana Trench is the deepest part of the oceans at over 36,000 feet deep. Little light reaches these depths and animal life is sparse. Temperatures decrease with depth to around 3-4 degrees Celsius at 6,600 feet. Humans can only cope for around 5 minutes at depths over 200 feet due to effects on the respiratory, cardiovascular and ear/sinus systems. Special equipment like diving suits, breathing apparatuses and surface supplied equipment are required for deep diving.