Wobble bench or home-made bandbell

5RNFT
Row 500m
10-15 (I lost count some times) x 20kg-ish bandbell (http://bandbell.com/) benches

The bandbell emulator was satisfactorily wobbly. I can see I need something to locate the bands securely the same distance from the ends and markings o  the dowel to mock-up knurlings.

The humidity was phenomenal and I'm sweating like a cold beer.
Now there's an idea!