Christy Garvin

Splash!

Our field trip to the Dive Shop was a huge success!   Everyone had a great time and enjoyed putting what we have learned into practice by actually getting wet.  Students had the opportunity to try out the scuba gear, and many of our students even braved the deep end with a dive master.  They were able to swim through underwater obstacles, turn flips, and even "hang out" upside down.  Students also enjoyed learning a few snorkeling skills for our upcoming visit to Discovery Cove.  I have attached a bunch of pictures and videos so that you can enjoy our special day as well!

 

 

 

 

 

 
 

 

 

 

 
 

 

 

 

Here are the links to some videos of our diving and snorkeling adventures:

Video 1 (4th)     Download 100_0715

Video 2 (4th)    Download 100_0717

Video 3 (4th)     Download 100_0734

 

 

 

 

 

 

 

Dive Tables

We are now into our second week of dive tables and students are making great progress in learning how to plan safe dives.   Dive tables or dive charts are tables used to determine the amount of nitrogen that is absorbed by a diver’s body. The charts offer a guide for the amount of nitrogen that can be safely absorbed while diving with no adverse health effects and provide allowable depths and times for both single and repetitive dives.

 Our class is using NAUI dive tables which are comprised of three separate charts: End of Dive Letter Group, Surface Interval Time (SIT), and Repetitive Dive Timetable.  Last week we learned to use the first two charts, and this week we will add on the third chart and discover how the table can be used in a cyclic manner to plan for multiple dives.

 
 As a culminating activity for our Scuba unit, we will be taking a trip to The Dive Shop.  During this adventure students will have the opportunity to try on scuba equipment, see videos from shark and stingray dives, learn from Dive masters and get in the pool to actually try snorkeling and scuba diving skills. This is a special trip and it does require students to demonstrate mastery of diving principles and dive tables before they are allowed to actually dive with the scuba equipment.  Students are aware of the fact that they must have a 90% on their dive table test before they will be allowed to dive.  This is a safety standard that is modeled after scuba agencies that require a 100% on a dive table test before an individual is allowed to complete an open water dive. 

 

All students will be able to attend the field trip, work with the dive masters, try on the equipment, and practice snorkeling skills for Discovery Cove, but actually diving in the pool with compressed air will require a 90% on the dive table test.  Students will take the dive table test the week of March 28^th and the test will cover dive tables only- no gas laws.  For students who do not make a 90% on the first test, there will be an extra help session Friday, April 1st at 7:20 a.m.  A second opportunity to demonstrate mastery will be offered in class the week of April 11th.  

 

In order to help your child be successful with the dive tables I have purchased some dive table software so that your child can come by in the mornings and practice as many problems as are necessary to ensure mastery.  This software is outstanding as it provides detailed explanations for any problem a child gets incorrect; there is a free version of this software if you would like to download it for use on your home computer.  This version allows students to complete an unlimited number of first dive, surface interval, and missing surface interval questions, as well as 20 repetitive dive questions.  Please use the link below to download the Table Tutor Software.

Table Tutor

Gas Laws

For the first few weeks of our scuba unit we have been learning about gasses and how they react to changes in pressure and temperature.  Our first topic of study was pressure; we explored the pressure that the atmosphere exerts on our bodies and compared that to the pressure of saltwater and freshwater.  What we learned was pretty amazing; because water is so much heavier than air, it takes only 33ft of saltwater to equal the same pressure (14.7 psi) that the atmosphere places on us.  In order to demonstrate the effects of pressure, we conducted the “Let it Flow” experiment and then used manipulatives to help us calculate the pressure of both salt and freshwater.  Here are a couple of pictures of students calculating these values.

 

 

After we had a basic understanding of how air and water pressure compare, we took a careful look at how pressure affects the volume of a gas.  “Squidy”, a Cartesian diver, was a great inquiry based experiment that allowed us to figure out the relationship between pressure and volume.  After a lot of trial and error, we learned that there is an inverse relationship between pressure and volume that can be quantified using Boyle’s Law. (P1)(V1)=(P2)(V2) It was a lot of fun to use Boyle’s law to calculate how long a given amount of air would last for a scuba diver at various depths.  Below, you can see some pictures of our work with “Squidy”.

 

 
 
 
 

The final gas laws we explored were Dalton’s Law and Charles’ Law.   Dalton’s Law is concerned with partial pressure of gasses.  Student’s learned that as divers go deeper and pressure increases, a gas begins to “act” like a higher percentage of that same gas would at the surface.  We then discovered that this principle can be used to explain things like oxygen toxicity, decompression sickness, and nitrogen narcosis. 

With Charles’ Law we explored the concepts of temperature, volume, and pressure; our important lesson from this law was not to leave a full scuba tank in the back of a hot car in the summer.  When the temperature increases and the rigid tank prevents the volume from increasing, the inevitable consequence is a change in pressure which can result in a burst disk on the tank.  Armed with a good understanding of diving physics, how gases react to pressure, and what can happen to our body if we fail to take proper precautions, we are now ready to begin our study of dive tables.

Diving: Exploration and Conservation of Underwater Ecosystems

 

Unit Overview

 "Diving: Exploration and Conservation of Underwater Ecosystems" is a unit that explores the sport of scuba diving and the responsibility that scuba divers have to protect and conserve the coral reef ecosystem.  As primarily a math and science unit, students will examine the impact of pressure on gases and will use the physics gas laws to explore concepts dealing with volume, pressure, density, and inherent lift.  Once a thorough understanding of the laws has been attained, students will relate and apply their new knowledge to the tables and charts used for recreational diving.  This will allow them to safely and successfully plan dives while taking into account factors such as depth, physical exertion, nitrogen absorption into the bloodstream and tissues, oxygen toxicity, and water condition. Students will learn how to calculate the lift required to remove objects from the ocean floor as well as exploring the physiological effects of diving on the human body.

 

In addition to the focus on the sport of scuba diving, students will also delve into a study of coral reef ecosystems.  They will discover why coral reefs are essential for our survival and will investigate the reasons that these natural treasures are endangered.  Students will learn about the methods scientists use to collect coral reef data and will examine things they can do to help conserve this resource.

 

The goal of this unit is actually twofold.  First, it is to introduce students to an exciting and awe inspiring sport that relies on the application of science and mathematics principles if it is to be enjoyed safely.  Students will see connections between the real world and the math and science they learn everyday.  In addition, the unit is designed to help students learn to value and appreciate the coral reef ecosystem and to empower them to make changes that will play a role in conserving this valuable resource.

 

Essential Questions

 How does an understanding of the physics gas laws contribute to the safe and enjoyable exploration of aquatic biomes using scuba equipment?

 

 How does the underwater environment affect the human body, and what can divers do to mitigate these effects?

 

Is the exploration and study of the ocean worth the inherent risks?

 

Why are coral reefs one of the life-support systems essential for our survival, and what is our role as stewards of these ecosystems?