Preface


We have been developing a variety of low-cost modifications to the original "CODE surface drifter" designed by Russ Davis in 1982. We keep the basic configuration/size the same in order to maintain the oceanographic-standard drag but try to use materials available at any hardware store. The idea is that the drifter can be built in any high school shop class, for example. It is a project in materials science. The more eco-friendly bamboo-framed "Cassie Drifter" and the wood-sail "Emily" drifter developed during the summers of 2013 and Winter 2015, respectively, are just slight variations of previous models. The "Rachel" and the "Eddie" drifter were our standards for many years but the full list of models is listed under the "Drifter History" tab. They all have a cross-sectional area of approximately one square meter and, since the electronic package is getting smaller, we have been able to further reduce the windage with each new design. The transition to using more biodegradable materials has been a real challenge. At the time of this writing, we do not have enough experience with the Cassie to estimate any good survival statistics but have had a few dozen underway. Our local ACE Hardware store began stocking these 4'-long bamboo sections that have maximum diameters of both 3" (for mast) and 1" (for spars). We suspect this bamboo will survive groundings with less damage than previous drifters that were fitted with 5/8" oak dowel spars. We continue to experiment. The most recent units developed are the aluminum-framed "Irina" drifter in the Fall of 2013 and the floaty-supported "Megan" drifter in the Fall of 2014 which show great promise in having easily accessible parts and being easy to build. Our current drifter model in use is the aluminum-framed “Irina” drifter, and we recently began using reinforced spars that seem to bend much less easily.

There are many different kind of drifter:

  1. cruciform shape
    • aluminum Irina drifter
    • wooden Eddie drifter
    • bamboo 3'' mast drifter

    Irina mount 2 mount 2

    Figure 1.aluminum Irina drifter Figure 2.wooden Eddie drifter Figure 3.bamboo 3'' mast drifter

  2. star-shape
    • bamboo star-shape frame drifter

    It is best to contact us prior to using this manual to make sure we have not made further adjustments and to get an update on the survival statistics. As we gradually make a transition between these different eco-friendly drifter designs, this construction manual covers the various options and discussion. A condensed version of the step-by-step procedure is provided in the Appendix.

    We also recently completed the directions for our turtle drifters, designed to imitate “cold-stunned” turtles. Technically these are another type of surface drifter. The directions for these drifters can be found by clicking here: Turtle Drifter Instructions.

    We also have completed the directions and drop down menu for our drogue drifters. Like most of the drifters used by oceanographers, these have sub-surface "drogues". We construct them with a small surface float which holds the transmitter and provides buoyancy for the drogue. We typically tether the drogue made from a series of "toddler play tunnels" sold online or at kids’ stores at about 12 meters depth using 1/8 inch stainless wire. The top part of the drogue is fitted with a 3-point bridle and the bottom is weighted to keep it vertical in the water column. While the “Tim” play-tunnel drogues are still undergoing testing,the results thus far look good.

    Thanks to educators Mel McFadden, Brandy Wilbur, Cassie Stymiest, Chris Ratley, and Lucy Lockwood for recent ideas and pictures below. We also thank students Dan Palance, Jen Troubetaris, Colin Sage, and Tim Anderson for their help these last few years.

    Jim Manning
    james.manning@noaa.gov


    21 August 2015