We have 2 portable stainless courses installed permanently on our river. Each end of stainless mainline is anchored with cement rings that they use for sewer caps. Course is held on bottom with bungees attached to cinder blocks. Balls are held on with adjustable bungees as the depth of river fluctuates. Balls are left in all season. We have not broke any of the pvc arms that go to the turn balls but we are constantly replacing or adjusting balls as MISkier said. On busy weekends other boats will run over balls and cut the line. Or pull the pvc arm and move cinder block before cutting line.