A nice catch & release style net

Plug rods

Fish club

Milk jug with bottom cut out or something to drain water from boat in heavy rain.

I would suggest getting an extra drain plug incase you lose first one.

Bow rope for walking boat around places you do not wish to row through.

Life jackets, even if you do not wear them I think it is required to have them in the boat.

Spare oar

Heaters are always nice in the winter

Ice chest to keep the beer cold