One fifth of all drownings can be attributed to suicide, according to figures released by Irish Water Safety.
An analysis by the association also found that the majority of drowning victims are men and that drowning fatalities decreased following a spate of tragedies last year.
There were 91 recorded drownings last year, which was the lowest number in almost 80 years.
In its annual report, Irish Water Safety found that there was a marked decrease in deaths following a two-week period last July in which 13 people drowned.
The association said the public had adjusted their behaviour as a result of the deaths.
In a wider analysis of statistics dating back to the foundation of the State, it found that three quarters of all drownings were male, and just over half of deaths involved people aged between 30 and 59.
It said 60% were accidental and 20% were attributed suicide.
The reasons for the remaining 20% of drownings were undetermined.
The average number of drownings each year has decreased, from over 200 a year in the 1980s to 135 a year in the decade to 2013.