I can usually do it in 4:
1 pair sneakers / walking shoes that I usualy fly / travel in
1 pair day sandals that can be worn with casual outfits at night or to the pool Mine have a bit of a wedge heel so they dress up shorts & still look OK with a skirt or sun dress.
1 pair water shoes
1 pair dressy evening sandals. My "cruise shoes" are high heeled strappy silver sandals because they go with everything: black, white, sequins, etc. It helps if you keep your eveing wear in the same color family.
Hope that helps.