Raw water strainer

[columbia]

How important is it to have a raw water strainer? None currently installed on my boat. If I get one, which model does the A4 community recommend? I have found quite a few made by Groco, Perko, and one by Raritan. Which is the best, and what size?
Thanks all

[Motor John]

I installed a Sureflow #254-266 on the suction side of the raw water pump. The only caviat I have for this is to check it often, as it has a small surface area can can get plugged quite easily depending on what the conditions are like where you are motoring.;) Most of the time it's fine, but occasionaly I have seen it get quite gunked up.