The number of people telling a campaign group they have become unwell after being in sea or river water has more than doubled in the last year.
The Water Quality Report also found there were 301,091 sewage discharges in England during the bathing season of 2023.
A government minster accepted the situation was "utterly unacceptable".
SAS campaigns manager Izzy Ross said: "The situation is as bad as it ever has been ... what we see is devastating.
"In England, we see 60% of the rivers that we did our citizen science testing on don't meet minimum safety requirements.
"They would actually be classed as poor under the Environment Agency's methods."
Reuben Santer was a secondary school teacher and got an inner ear infection after going surfing at Saunton Sands in Devon.
He said: "I couldn't walk or anything - I was properly bed-bound for a few days.
"At points, it was so bad I had to close my eyes for five or six hours because everything was just spinning round and round and round, and would make me throw up.
"I have lost my job. I was off sick for 45 days and multiple days where I ended up being sent home from work.
"I say sent home; I had to have a colleague to drive me home or friends to come and pick me up because I had attacks of rotational vertigo."
The cause of his problems is not provable, but Mr Santer said his GP believed polluted water was likely to be responsible.
'We need action'
In a statement, the government's minister for water, Rebecca Pow, said: "We agree the volume of pollution in our waters is utterly unacceptable."
She added the government's water plan will "deliver more investment, stronger regulation and tougher enforcement to ensure every overflow is monitored".
Water UK said it was going to spend £11bn over the next seven years to tackle the problems.
Ms Ross said: "It is great to hear these things, but we need to start seeing action.
"We need the government to enforce the laws they already have, which they are not really doing at the moment.
"We need the regulators to be properly funded.
"Yes, £11bn from Water UK is great - we heard an apology from them back in May ... but we want to see action rather than just words."
For Devon and Cornwall, South West Water said that, over the last two years, it achieved "100% coastal bathing water quality compared to 28% back in the 1990s".