Pretty generic title I know, but more particularly wanting to get opinions about Fremantle area's favourite protected beachie. The groyne has at least doubled in size compared to back in the day. Has this affected wave size?

Theres always a way out of any tight place!

hi sparki
do you mean a beach close to a port?

the main things i can think of that might increase the wave height due to a modified groyne:
- does the groyne/wall now cut off the angle of approach of seas/swell as you observe it, compared to before, eg. if it is 100s of meters long - not sure it does if I'm thinking of the right one, plus there is some refraction effects if the swell is very south - but it is in Cockburn sound just about...
- has the groyne/wall been made more rough (sorry, basic term only) eg. larger rocks, bigger voids between them, and so it is absorbing more wave energy and not reflecting it as it may have used to (reflected wave superimposing on the approaching waves and making it feel bigger ie. wedges). I have no idea.
- has the offshore bathymetry change drastically due to the structure or incidental to the structure. I don't think that would be the case off the freo coastline from my observations

I have a mate who is a coastal eng that grew up surfing around there and sandtrax etc during the right wintery conditions, so i'll ask him when i see him next as well...


oh, and to fit in...

if groynes are a sore point, I find rubbing it helps...

I reckon sandtrax has changed for sure over the last 10 years since it was filled in.

what was the other break called that was completely filled in, basically it was the inner bit before the ferry terminal. I think I can remember surfing it a long time ago and coming out smelling like petrol..... although sandtrax is like that too now. My missus knows straight away when I've surfed it haha

lfc said..
I reckon sandtrax has changed for sure over the last 10 years since it was filled in.

Yeah? How do you reckon so? Genuinely interested. When I first realised what the developers were doing (extending the groyne), I thought the worst. Surfed it recently for the first time in ages, didn't think much had changed, but keen on other opinions. Seems like another break is being threatened every other day, sometimes they're changed forever, sometimes not at all.