Mine, and I suspect all triathlon watches on the market, have a race feature to track swim, bike, and run during a race. I know I am not the only one who has had problems switching between the different sports during a triathlon. I have forgotten which button to push to move from the swim to transition 1 etc which has screwed it up. I know of others who thought it would know when you are done with each sport…but it doesn’t switch over on its own. But those human errors aside, it is really nice to track each event and transition times for a race. And you can set it to take all settings for each individual sport to the race. In other words, if I have the run/walk feature turned on for running, it will also use give me those alerts for the run.
You certainly don’t need any of this data tracking to complete any distance triathlon. However, I think it is probably the biggest bang for your buck when you do start investing in anything tech related for training. Well, the watch and a heart rate test to train using accurate heart rate zones.