The temperature in the water around Monterey Bay varies dramatically throughout the year.  Upwelling caused by winds during the summer brings nutrient-rich water from below, but this water is very cold.  This previous summer, the water was around 50 degrees Fahrenheit or 10 degrees Celsius – thats chilly!  To go explore the ocean by snorkeling or SCUBA diving you want to be warm to focus on all of the amazing marine life around you.  One way to do this is to create a layer of air or nitrogen between you and the water.  Neoprene wetsuits are composed of foam with nitrogen gas inside, creating an insulated wall to help slow heat transfer between you and the cold water of Monterey Bay.  The other option for staying warm is to purchase a drysuit, but these suits are more expensive and require further training.  Whichever you choose, get out into the water and experience Monterey at its finest.