Mapping and Physical Data Procedures
The main products of the Map Team are
site maps, physical data reports for each dive on the site, and placement and maintenance of ID markers
at specific locations on the site for use by other specialists. Tasks consist of reconnaissance surveys
of a site and its surroundings, measuring physical dimensions of sites, creating, placing and maintaining markers for
ID stations, GPS measurement of landmarks on the sites, pathfinding for navigationally challenged
ID specialists, and collecting and inputting physical data for each dive.
Mapping is generally done with two or three person teams.
On new unmapped sites, the mapping leader and mapping team members will perform a reconnaissance
dive on the first team dive to the sites. They will do an overall sketch of the site, identifying
prominent features that would be easily found by other dive team members on subsequent dives to
the site. They will also observe where fish tend to aggregate, as potential locations of fish ID stations.
Once benchmarks are installed (see below), the mapping team members will begin to map
the site with the tape measures, compasses, depth gauges, and GPS.
The relationship of the benchmarks to one another will be established by both distance and bearing
(azimuth readings), and other portions of the reef will be mapped in relation to the benchmark
Physical Dimension Measurement:
Mappers will measure the distance between two points underwater by reading the numbers from
the reel-type tape measure they stretch between the points, and my taking the compass heading the tape makes when tight. Generally, two members should start at the same position, with one remaining in place to hold the tag end of the tape while the other plays out the tape from the reel as he/she moves to the point to be measured. When there, the tape is stretched tight and the measurement written on the slate. They will each sight along the tape measure when it is stretched taut between the two points and obtain an azimuth bearing on their individual compasses. Their readings should be 180 degrees apart, and within 5-10 degrees of being the reciprocal of their partner's reading. The average of these two readings is taken as the measurement. Measurements are made from benchmarks
to other features on the site. On larger area sites, mapping measurements generally begin at a
benchmark and continue in one direction utilizing multiple measurements as limited by the tape
measure length, visibility, and currents.
Physical Condition of Wreck Structures:
On dives where ships are being utilized as artificial reefs, a physical inspection of all the structures involved will be conducted, and the results included in the written report. Where feasible, wide angle photographic evidence shall be taken to establish a chronological record of the wreck's deterioration over time.
GPS measurements of major landmarks on the dive sites are obtained using GPS equipment floating on
the surface and towed by a diver. This system was devised by a PBCRRT member and is in use in over a dozen
locations throughout the world.
The following physical data shall be recorded for each dive on each site:
The physical data is collected utilizing the following methods:
Tape measures will be used with Secchi disks or white diver slates to measure underwater water visibility. A tape measure is played out until the Secchi disk or a diver's slate is no longer visible by the diver with the reel end of tape. The distance is then recorded as visibility. These measurements should be taken near the surface (within 15 feet of surface) and a few feet off the bottom of the dive site on the reef.
Once collected, the data is to be entered into the database using the online data entry form, which automatically produces an online and printable report page for use in the report cycle.
ID Marker Placement:
In collaboration with the Fish Leader, Invertebrate Leader, and Science Coordinator, the Map Team
will determine locations for fish surveys and invertebrate monitoring on a site. They will construct
permanent plastic markers containing contrasting alphanumeric lettering to be used to identify
specific locations as fish ID stations or for invertebrate photo surveying points of interest.
These markers will be affixed to concrete blocks or steel stakes brought to the site, or attached
directly to limestone rock or concrete rubble already on the site.
Photo and Video Techniques for Map development:
Mapper Certification Requirements:
Mapping is the most task loaded of the specialties, requiring an ability to cope with upcurrent swims, poor visibility, and hands full of equipment. It also requires experience in navigating the various sites the Team dives, which can only be obtained over time by actually diving the sites. To be obtain the Mapping Speciality Certification: