Eyemouth in the borders was one of 18 beaches which failed
The water quality on Scottish beaches has gone down since last year, according to a report from an environmental group.
The Marine Conservation Society (MCS) said there had been a 10% drop in the number of recommended beaches.
Its annual Good Beach Guide also said beaches failing the minimum legal standard had more than doubled to 18.
The MCS blamed the drop in water quality on an increase in storm pollution.
Bathing water tests coincided with the wettest summer in Scotland for 30 years.
Five of the beaches which failed were in Ayrshire.
Calum Duncan, the MCS Scottish conservation manager, said: "These latest MCS results buck the long-term trend toward cleaner bathing water but we're pinning the blame on last summer's exceptionally bad weather.
"Heavy rain sweeps pollutants like raw sewage, street debris and animal waste directly from the land into rivers and the sea."
The MCS said the problem for swimmers was knowing when and where this had happened.
In May last year, the group warned that storm run-off from city streets, farm land and combined sewer overflows was hampering efforts by Scottish Water and the Scottish Environment Protection Agency (Sepa) to improve bathing water quality.
The guide recommended 44 beaches this year - more than triple the total in 1998.
The MCS suggested that the £3bn invested in sewage treatment and infrastructure over the past seven years had brought permanent benefit to Scotland's beaches.
The society said electronic forecasting signs advising swimmers about beach water quality had been a great success and it would like to see more of them.
Mr Duncan added: "We also now need serious investment to tackle pollution from the hundreds of storm overflows around the coast and the more than two dozen outfalls continuously pumping poorly treated sewage into the sea.
"MCS is very supportive of the strategy and action plans adopted by Sepa and the Scottish Government to tackle coastal pollution but we equally have concerns that Sepa has reduced bathing water testing by more than 30% since 2003."
MCS only recommends beaches if they are better than the guideline European water quality standard and are not affected by inadequately treated continuous sewage discharge.