While I have long been interested in cars, usually little sports cars from Europe and Mountain Biking, my first joy was boats and sailing. Due to these widely ranging interests, I can thankfully think a little out of the box to solve some issues on Spark.
As an ex-racer, my boat has little no storage, not that any GP ever did -they are only 14 feet long. As a General Purpose boat though, the ability to go most anywhere is a given. To follow that directive, I needed to think outside of the (boat shaped) box to my other hobbies.
Anybody who was ever remotely serious about bicycling will tell you that staying hydrated is very important. The only way to store liquids on a bike are frame mounted bottles. To make it easier to keep from getting thirsty while sailing, I decided to steal that concept and purchased some frame mounted bottle holders from the local bicycle shop.
Being made of black plastic and adjustable to fit any size water bottle, these should keep me well hydrated when I cannot reach for the cooler. I screwed them into the supports for the benches closest to the stern. One bottle on each side should do nicely.
On the inside of the support you can see a similar mount. I am using this to keep my air horn close at hand if it is needed. The horn itself is interesting. it is refillable from a standard bicycle air pump. One of my pet peeves are "one time use" items where you use them and throw them away. The CO2 canisters used by most hand held air horns bug the hell out of me.
Next on the list is storage netting. While things will still need to be bungied together, keeping items up in the bow or under the stern is always a big deal on a small boat. Borrowing once more from my sports car hobby, I trekked over to the nearest automotive store and bought two trunk nets. These woven nets made of a bungee like rope allow me to stuff all manner of things under the decks without them working their way out in rough water or in the event of a knock down.