In order to gain access to allow me to install the backing plates on the additional grab rails, I had to cut holes on the inside hull liner on the port and starboard side. To make the job neater, as well as make use of some additional storage space, I was able to find these 6" watertight screw-in combing boxes.
They don't offer a lot of storage, but are great for a rescue throw rope storage and other smaller items that might be required on deck.