I use the seasense ones from Wal-Mart. They work great. I would just rivet one to the side of your bench.
https://www.walmart.com/ip/Seasense-Adjustable-Drink-Holder/16778799
I use the seasense ones from Wal-Mart. They work great. I would just rivet one to the side of your bench.
https://www.walmart.com/ip/Seasense-Adjustable-Drink-Holder/16778799
I use small canvas bags that have clips on them. We used to use them on our climbing body belts to hold hardware. Maybe something like carpenters use on their belts. I just clip them on whatever is available at the time, like the oar locks, bench seat braces, etc.