First timer... estimating swim time

[Gaius]

Hi,

Planning my first triathlon this year, was interested in the BelPark Blessington race at the end of June, but to enter I need to estimate swim-time and... well...

a) I hope it will be a lot better by then...

b) I don't know how I would estimate it...

If I time myself over, say, 4lengths / 100m in a 25m pool and then do a straight multiple, is that valid? Or does it need to be more accurate than that?
Thanks,
G
ps: Not worried about the distance - as can do more, easily, in a pool... but the open water will be new, as will swimming in a wet suit.

[Frank]

Hi
This is not the most important thing. When races ask for times it is so they can group people of similar standard in the same wave. F

[Gaius]

I’ll try to estimate something from pool times, then.
Thanks,

[Gaius]

AHA!
www.ironmate.co.uk/swim-time-prediction-tables
The only question being whether race pace is "as fast as I can go" or "as fast as I can go and still have the breath to swim another length".
G

ETA: Ok, so neither of those then! www.triradar.com/training-advice/triathlon-swimming-dial-in-your-race-pace/