I have a 3200 Open, but in general a heavy duty / winter RV saddle mount set (reuse the stainless bolts) will work well and last several years even in salt water if you need the whole arm. I used these this year, just measure the length and order appropriately:
https://www.amazon.com/gp/product/B07H4D...UTF8&psc=1
https://www.amazon.com/gp/product/B07H4D...UTF8&psc=1
