The “surface drifter” was first introduced to the oceanographic community by Russ Davis (USC) in the early 1980s and has remained the standard for tracking surface flows in the ocean. Beginning in 2003, we developed a low-cost version of this configuration. Built primarily by students at various schools, the drifter has evolved over the years to be easier to build, less costly, and involve much less plastic.
Standard Surface Drifter “Irina”
The most recent version, called the “Irina”, consists of a 1″ square aluminum pipe mast supporting a transmitter, a set of 4 canvas cloth sails (19” by 36” each), and a net-buoy flotation collar. The sails are held in place by a set of four aluminum spars (3/16” x 48”). The unit can be assembled on deck in 10-15 minutes each. While these units do not survive multiple years as in the case of commercially available units, they do typically provide multiple months of tracks at a user-specified sampling rate (30 minutes to 1 day).
DIY Standard Surface Drifter Kit
For those willing to invest a few hours into building their own surface drifter, we supply the hard-to-find parts (transmitter & flotation) in the form of a “kit”. Along with instructions and a shopping list of the other components (available at your local hardware or lumber yard), we supply the support to help you build your first unit as well as the data access and website to track your drifter. It is important that all surface drifters comply with the oceanographic standard as described above in the ready-to-assemble & deploy option.
For those looking to track a deeper subsurface current, we supply the drogue, tether, surface float, and tracker needed to do so. We follow the oceanographic standards in configuration to provide the 40-1 drag ratio spec as set by the World Ocean Circulation Experiment. The tracker is mounted above a standard lobster buoy which then supports a tether at a user-specified length down to the swivel, bridle, and drogue.
For those looking to build their drifter from scratch according to oceanographic standards, we provide the tracker, the technical support, and the website tracking. The tracker is shipped pre-sealed, pre-provisioned, and, if needed, pre-programmed to the user-specified sampling intervals.
The GLOBAL STAR service provider charges fees for:
- provisioning each unit ($30/each)
- annual maintenance fee ($30/each)
- fix ($0.15/each)
For example, if you plan to have your unit recording twice per day for 3 months, the fees amount to 30+2.45*3+2*30*3*0.15 = $64.35