Many years ago we had a few pieces of equipment that we used to enhance our swimming. They are still in use today, along with a few others I never would have thought that exciting, but you can teach an old dog new tricks and I’m happy to report that I would recommend a snorkel for your swim training. I’m going to also highly recommend ankle straps and incorporating resistance band training.
Here’s an article to read on snorkels:
Also…after many years of adapting competitive swimming workouts for triathlon here’s a different outlook on swim”drilling” and some new thoughts on training for triathlon specific & open water swimming that I am excited about: https://youtu.be/UNB_CfHkFM0?list=PLy-o4cLplcwVZWohng7BZSb2sCI97hdQx
By the way some of this equipment, like the resistance bands were consistently used in our age group training as were the ankle straps….somewhere along the line they got dropped – probably because they make things challenging. Glad to say I’m rediscovering them.