Equalising techniques can be a very personalised and although you may have a way you prefer or have naturally adapted to, it's important for dive professional to have an understanding of the mechanics of a variety of techniques.
All students are different and helping them through equalising issues can be one of the most important things you do for them if it's something they are having difficulty with.
You may also find that experimenting with various techniques and hybrids may allow you to explore new diving discipline such as Freediving too.
The phenomenon of light waves bending when passing from one medium to another is called refraction and is the reason objects appear larger and closer while we are diving than they actually are.
The air pressure at altitude should always be taken into consideration whilst planning altitude dives as it will be less than 1.
This will alter no-decompression models of any dive planner or dive computer. Most dive computers now have altitude modes that can be set and adjusted during altitude diving expeditions. Special consideration must be taken into acount when using the RDP and eRDPml when planning altitude dives.
More information on these considerations such as the reduced ascent rate may be found in the PADI Advanced Open Water Diver materials as well as the PADI Altitude Diver Specialty Course.
The latest version of the PADI Instructor Manual has a great table in the Advanced Open Water Diver section indicating who may conduct which Adventure Dives as a quick reference tool.
Although many Adventure Dives may be conducted by an Open Water Scuba Instructor some must be conducted by a Specialty Instructor in that PADI Specialty; Adaptive Support Diver being one.
Similar to last weeks question, if you don't know what the markings on a cylinder mean don't assume they're unimportant as cylinder marking can vary from region to region.
Many diving cylinders are manufactured in the U.S. so it's very common to find DOT stamped on to the side of your cylinder.