Preparing the Flotation
There are multiple ways to secure the flotation depending on the type of drifter and the type of flotation you have available. Shown below are some examples we have used. The number of floats used obviously depends on the size of the floats you are able to obtain. The important thing is to test your final configuration in water prior to deployment. In the case of wood and bamboo masts, keep in mind that the drifter will submerge a few inches after being absorbing waters for days. Whatever method you use, we suggest having the transmitter ultimately located about 7" above the waterline. There should be at least another 7" between the top of the sails and the flotation. See the recent example of the aluminum Irina and Megan drifter configurations in the figures near the bottom of this page. It is particularly important to prevent the sails from being exposed to the wind. This is the reason we talk about a "mast extension". Since some of our masts only come in 4' lengths, we often had "mast extensions" .
- Slide flotation buoys through the mast extension BEFORE securing the mast-extension.
- Secure a hose clamp or similar stopper above and below the buoys to prevent vertical slippage. Position there is about 6" of pole above the float (exact distance will slightly each unit).
- In some cases such as in the old wooden Eddies, we install a collar of buoys at the very top of the mast (see right-most pics below) held on by a hose clamp and secure in place by a stopper.
- Note: One image below shows three floats stacked on an upside-down ski pole with the tip sawed off. In this case, we lash the transmitter to the basket of the ski pole.
But what to do if you do not have easy access to floats? Here are a few options:
You can buy it from here
Make your own with 2-inch insulation foam.
This idea comes to us from the 8th graders at Newburyport MA Junior High with modifications by Conner Warren, a Hollings Scholar intern during the summer of 2014. We show below a cone-shaped buoy hoping that it will minimize the windage but we are not really sure the extra labor in forming the cone is necessary. The first prototype was a 6" by 6" cylindircal-shaped foam that lasted more than a month before coming ashore. The 2nd prototype was cone shaped and will be tested during the summer of 2014. After the final rig, we include a series of photos that highlight some of the steps in building it. Note that this 2" pink insulation foam is available at most lumber yards in New England. On 2'x8' sheet cost about $25 but should make nearly a dozen floats. We sandwich three layers between a few pieces of exterior plywood. We drill a 15/16" hole through the center of the foam and a 1" hole through the center of the plywood in order to insert a 1" aluminum square pipe mast extension but that hole depends on what you are using for your "mast extension".
Make your own with marine urethane foam.
The next alternative is to buy a set of 2-part marine urethane foam solution and make your own buoys as we did in the case of the Domino sugar container below. In this case, we insert our mast extension ahead of time, tape around the edges so the solution stays in the container before solidifying, and you can make your own ""closed-cell-foam" buoys custom-shaped depending on what containers you have. We have also made floats using plastic milk jugs and salad bowls. No need to remove the molds in these cases. Yes, they are plastic but at least we are reusing the plastic.
Make your own with a "floatie".
This final alternative, being tested in the Fall of 2014, is to use "floaties" as available at most department stores. This idea comes to us from "Liam", a high school student from New Brunswick Canada who participated in a Gulf of Maine Institute drifter-building workshop and "Megan", a Falmouth Academy student who built and tested the idea for her science fair project. Her drifter was also the first to use the heavy-duty 12mm driveway stakes (see picture below).