I was recently looking at a article about swimming tips for racing and open water. It talked about the concept of practicing the deep water start. In this context, deep water means any type of swimming where a person would have to start from the stopped position and where they had nothing to push off from. Push off would be the bottom of the pool/ocean or the side of a pool.
The reality is that there are many swimming/triathlon events, where the start of the event is in the water and not on shore. Or, a case where a swimmer has to stop to possibly site on the course or because of bumping another swimmer. A swimmer should practice sighting on the swim so they do not have to stop, but it can still happen. These types of starts are required and you should be ready to start quickly to get up to swim speed.
The article suggests practicing in a pool. The swimmer should be away from the wall for the start of the drill. Then swim 1 lap or 2 lengths for a minimum of 50 yards. It is recommended to do 6 to 8 sets.
While it may not seem to be a big deal, stopping during the swim does eat up seconds. Especially if there is a small current that is fighting your direction to the end. Going from a complete stop to full speed for a race does eat up seconds too and doing this bit of training, plus training on how to site during a swim can really help. If you can site while you are swimming to not stop and minimize the amount of time required to go from a stop to full speed, you can save many seconds. Seconds that can make a difference!
Hope this helps with a little tip and guidance for a better swim