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Catalina Buoy versus Crystal Cove Beach

by Anonymous Students (names withheld by request)

Weather buoy #46025 anchored off Catalina Island


Our daily lives revolve around what the temperature is outside on a particular day. Surfers also need to know temperatures of the seawater to see if it is too cold or just perfect for a day of surfing. Fishermen are another group of individuals who need the seawater temperatures to know where they are going to get a good catch. Our group investigated the temperatures at the Catalina Buoy and at Crystal Cove beach to see if it is possible to predict the Sea Surface Temperature at Crystal Cove by looking at the current conditions at the Catalina Buoy.


To get the air and water temperatures at the Catalina Buoy, we went to the National Data Buoy Centers' web site ( and looked up the Catalina Buoy (# 46025) and it gave us the air and water temperatures for the past twelve hours. That was the easy part. We then went to Crystal Cove beach and took air and water temperatures every ten minutes. The beach at Crystal Cove is covered with lots of small rocks and a few very large rocks, which threw our readings off due to their heat absorbing properties. To take the water temperatures at the beach, we purchased a floating pool thermometer and attached a very long string to it for easy retrieval. We would climb onto one of the larger rocks, so we could get farther out into the water, and we threw the thermometer into the water while holing on the string of course. Then every ten minutes we would take it out of the water to get the reading. We had a second pool type thermometer suspended by its' string to get air temperatures, and again we took readings every ten minutes. We then compared the data from both locations, which were taken at the same time (1-4 P.M.).


[note: this is not a properly written results section]

With the little time and small number of readings we could get, we are nowhere near being able to predict the temperatures at Crystal Cove Beach. Crystal Cove is a complex beach; it has large rocks, small pebbles and lots of kelp to through off temperatures very easily. There are also a number of sewage streams that flow into the water at Crystal Cove that also affect the temperatures. We did note that at the beach, the air temperature was always higher than the water temperature, and at the buoy the water temperature was always warmer than the air temperature. With more data and more testing sites we may be able to determine if it is possible to predict, with some error, the water temperature and or air temperature at Crystal Cove beach by examining the conditions at the Catalina Buoy.


The high tide and the rocks that were present at the beach may have affected the wild readings we got. If we had gone to different locations along the beach where there were no large rocks but only pebbles or to where there were no rocks at all, we may have gotten a more accurate reading. We could have also have taken reading at beaches north and south of Crystal Cove to get a wider sampling. Another way we could have done it, would have been to take readings in the morning, at mid-day, in the afternoon and at night.

References: National Data Buoy Center ( Oceansonline (

Tables and Graphs

Figure 1:  This graph represents the relationship between the air and water temperatures during week one at

Figure 2: This graph shows the differences between the water and air temperatures during week two at the Catalina Buoy.

Figure 3:  This graph shows the relationship between the air and water temperatures at Crystal Cove the first week.

Figure 4:  Shows the differences between the air and water temperatures at Crystal Cove