Michael is the fastest swimmer on his swim team. He wants to get some extra practice time in so that his flip turns are even quicker than they are now. He enters the pool 15 minutes before everyone else arrives to work on his technique. Based on the information provided, which safety procedure is Michael forgetting to follow by practicing his flip turns during this scenario?

Check the weather forecast prior to swimming
Don't dive in shallow water
Know your swimming ability
Never swim alone