Enjoy The Mayhem
Mass starts are a physical challenge, but handling them well is more of a mental game. There is nothing you can do to change the behavior of others, so turn the negative into a positive by having fun with the rough-and-tumble. Yes, fun. Think of the crowd as a protective family group. Welcome every jab and kick as a reassuring pat on the back and let them energize you. Don’t be startled by body contact; expect it and roll with it, literally. Swimming with more body rotation makes it easier to slip between other swimmers and also it makes it harder for others to go directly over you. Be considerate of others and forgive their trespasses.
In practice, cram your buddies together (the more the merrier) and swim in a tight group. Then hit the gas and take turns moving through, around and over each other to the front. If you have the right attitude it will be easy to stay in your circle. Have a good time. Mob swimming is fun in practice. Let it be fun on race day too.