Oceanography | Vol. 38, No. 3
84
FIELD APPLICATION
STUDENT DESIGN AND DEPLOYMENT
The seven teams (six student teams and one instructor team)
explored various design approaches, varying the size and shape
of the drogue (cross-shaped vs. square-shaped), the drogue
depth (ranging from just below the surface to 15 m deep), and
the placement and distribution of weights and buoyant materi-
als. Additionally, some students incorporated store-bought coco-
nut shells and locally sourced cane as supplementary buoyancy
materials (Figure 4). During testing, they adjusted buoyancy by
modifying the float and weight, checked the drifter’s ability to
self-right after capsizing (Figure 5), and validated both the com-
mercial and the custom GPS tracking systems.
The drifters were deployed nearly simultaneously from the
same location along the coast of Faial Island, Azores, Portugal,
with photos of the deployment from the boat shown in Figure 6.
The drifters communicated for 12 to 36 hours before being lost
at sea, with the furthest transmission recorded at approximately
11 km from the initial drop-off point. The loss could be attributed
to the drifters traveling beyond the range of the LTE-M signal,
a mechanical failure that caused them to sink, or an electrical
short circuit due to water breach.
FIGURE 5. Before installing the GPS units, students
tested the buoyancy and survivability of the drifter in
ocean water along a loading dock. Students used the
results of these tests to adjust buoyancy devices.
FIGURE 6. Drifters were deployed
from small boats and were released
at approximately the same time,
12:00:00 on July 17, 2023.
FIGURE 4. Before building began, teams worked on planning and designing
the attributes of their drifters. (a) This sketch depicts an initial student drifter
design employing natural, locally sourced cane found by one of the students
living on Faial. (b) The corresponding drifter, built according to the sketch,
is shown during the testing phase. (c) Student teams spent about 10 hours
designing and building drifters over one week. Teams were given access to
basic hand tools.