If you do not have a genset, try this. On my old Sailfish, someone had built an empty box with no lid then dropped it into the bilge area, under the bench seat. Two stainless screws went into the bottom of the box and into each of the two stringers that the box sat on to hold it in place. This is in front of the Batt Switches but the sides of the box were low enough to still operate the switches. The box was used for all types of storage and it could easily be removed if a bilge pump needed changing, etc. A heavy-duty plastic storage bin from Target or Lowe's might also fit down into the opening and you have the option to use or not use the lid.
Also, if you do not use the livewell, that's excellent storage as well.
Under the mid-berth floor panels is great storage for things that you want to have aboard, but hope you never use, like spare props. Here are my spares, greased up and on either side of the head holding tank under the aft mid-berth floor panel of my Marlin..... Note: the trough that runs from the Fwd bilge area to the Aft bilge area runs under the head holding tank, so these props are
not sitting in the bilge.