Dia daoibh, nílm cinnte faoin aibirt seo

"cé go bhfuil bratacha ann nach bhfuil cead ag na snámhóirí a shnámh thar..."

Im trying to say, even though there are flags there that thw swimmers are not allowed swim past...

An bhfuil sé ceart go leor?

GRMA

It depends ...

Direct speech:
Deirim: "Cé go bhfuil bratacha ann níl ceart ag na snámhóirí snámh thar ..."

Indirect speech:
Deirim cé go bhfuil bratacha ann nach bhfuil ceart ag na snámhóirí snámh thar ...

In both cases no need for "a shnámh".

I'd say it should be 'snamh tharstu' (assuming 'swim past refers back to 'the flags'.

I agree with Labhras re 'snámh' vs 'a shnámh'. You'd use 'a shnámh' with a preceding direct object - e.g. distance/river they're not allowed to swim. If an indirect object , as in this case, with a preposition - e.g. distance they're not allowed to swim beyond/river they're not allowed to swim in - then it's just 'snámh' without 'a'. Though I'm sure you know that already.

Re 'thar' vs 'tharstu', I think Labhrás may not have interpreted the English accurately.

Seans maith.
I have really no idea what kind of flags is meant
So, the sense of "nach" is actually final? flags to show that swimmers aren't allowed to swim past them?
(in this sense "nach bhfuil" is necessary, as well as "... tharstu")

I rather thought of flags on a beach to show that swimming is safe on that day.
But though there are those flags it isn't recommended to swim beyond something else, e.g. buoys: ...thar na baoithe nó a leithéidí.)