My daughter was timed swimming off the wall just recently. She was able to get the fastest time of 1:11 for her 100 yard free about 6 times. If she were to dive off the block, what would her time be approximately. Someone told me to take about 3 seconds off of her off the wall time. Is that true?
It's a difficult question to answer accurately because it depends so much on how good her dive technique is. Age, strength and technique will make a big difference to how much benefit is gained from a dive start versus pushing off the wall.
For example I'm an adult male and a sprint swimmer so I would expect to make the full 15m underwater from a dive start and would estimate it between 2 - 3 seconds versus a push start. This is based on my max effort 50 metre free from a push start is about 27 seconds but my race PB is 24.5 so that's 2.5 seconds faster.
I would say if she is a younger swimmer then allow 1.5 - 2 seconds maximum for the dive unless she has a very strong dive in which case perhaps up to 3 seconds maximum.