All plates and drinking glasses should be Plastic. No glass on a rocking boat.
You can use Lock-N-Lock containers or other waterproof containers and store stuff carefully in the bilges if you need extra room. Keep things organized, a neat boat will be far more comfortable than a messy one.
A fixed or temporary clothes line will help dry wet items with good ole solar power.
If you have a ice box, BLOCK ICE works better than cubes, and remember, the ice goes up high in the icebox.
Have a few more ABC fire extinguishers than required in strategic locations around the cockpit and cabin ares, just in case.
When on the boat IMHO every one should have a sharp fixed blade knife and a set of wire cutter (side cutters) pliers or a quality multi-tool on their person at all times. A rule on my boat. You never know when you might get tangled in the rigging or lines. A few seconds saved can save you life.
Don't forget a weather alert radio.
Spray covers for your dingy/tender will help keep you and your gear dry during shore trips.