On an extended sailboat trip you have to travel light, but what you do have must be there when you need it. If you are anchored in a quiet bay, there is no problem: You have all the time in the world to find it. However, if you are in an emergency in the middle of a storm, puking from sea sickness, and crawling across a heaving floor, then finding a misplaced item becomes a crisis.
As first mate on a long voyage, I spent a lot of time moving items from locker to locker, depending on how soon we might need them and where we would need them. The spare compass had to be close to main steering station in case our auto pilot and compass both failed (and they did). Tools were stored in waterproof labeled containers and placed near the engine in case salt water leaked into the engine (which it did, twice) and had to be expelled immediately. Even the spare toilet paper was within reach of the toilet.
Also, I had to remember where everything was stored because my captain did not remember. Friends on a 33-foot sailboat, who lived aboard in the Caribbean for 10 years, solved this by keeping a master list of items and locations. One evening, we were aboard their boat, preparing to share dinner with them, when the first mate searched for a bottle of wine and discovered that the captain had not been updating the master list. She was furious. Furious. She never found that wine.
Another tip is to check every locker periodically. It might be time to move items to a better location or just to remember what is in the locker. Most of our canned goods were stored under the floor in the galley (kitchen). When we were trapped in a harbor by a storm in Nicaragua, I decided to check out all my galley storage. When the lid came off one of the lockers, a horrible smell filled the galley. I near gagged from the odor and ran for a gas mask (I don’t know why I had one). The captain put a wet rag over his nose and mouth. We found the locker filled with black, bubbling goo. Salt water and diesel fuel had leaked into the locker, and as a result the cans deteriorated and disintegrated. The contents spilled out and mixed with each other to become the worst stew ever.
So to avoid black goo stew and be ready for anything at any time, make sure your lockers are sorted, arranged, memorized, and inspected on a regular basis. Now that we live in a house, I’ve been organizing and rearranging closets rather than just stuffing more into them and the result is that we rarely have to shop for anything other than fresh food.