For me personally urchin or whale ,
used both but had a whale gusher for over 30 years on a fishing boat that gave no problems & it had the original rubber diaphram throughout ,
suppose if its exposed to sunlight it will perish faster as well as how rough you use it , using extension handles plus trying to beat its maximum flow all have an effect as well as how much the lift of water is though on a rib it won't cause problems.
having a strainer helps to keep out seaweed , plaggy bags sweet wrappers ,
I used a plastic washbasin overflow fitting that fitted a half inch diameter pipe ,
on the end of mine having a 90deg elbow kept the pipe laying flat and it acting as a strainer/ filter.
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