About Us

Hello, My name is David Gentry, the Creator/Inventor of the Blue Marlin Filter
System(US Patent # 6,394,706). As a licensed marine contractor, In 1996, I
started a company called Blue Marlin Marine Construction Incorporated located
in Naples Florida. This is the developmental history of the Blue Marlin Filter
System. While repairing a seawall suffering from drastic erosion problems, I
became aware of problems with the weep holes. The weep holes, within the
seawall panels, were either clogged and not allowing ground water to escape, or
the weep holes were free from the filter fabric and allowing soil and landfill to
escape through them into the canal. The normal procedure would be to inform
the homeowner that heavy equipment would be needed to dredge out from
behind the seawall and replace all the filter fabric along with back-filling the
seawall with the proper materials. Quite a costly venture. A seawall, or bulkhead
has various functions. With its weep holes, it is to relieve hydrostatic pressure
put upon it by the ground water developing on the landward side of the seawall.
It should prevent erosion from occurring to maintain the dignity of the
landowners’ property. Therefore, its functions are to keep the soil and land in,
and allow the water from the landward side out. While successfully repairing this
particular erosion problem on this seawall, I deemed that the weep holes were
still a problem that had to be dealt with. How could I replace the filter fabric (that
which was clogged and parts missing) without going to my customer with the
expense of using heavy equipment and dredging, also realizing that the same
procedure will again be needed in the future? With my customers high
maintenance costs in mind, I designed an erosion control drainage system called
the Blue Marlin Filter. The Blue Marlin Filter is made up of ABS UV protected
cylinders with a 2” diameter available in various lengths. First, is the 3” design
made purely for the corrugated sheet pilings. Second, is the 9” design (blue in
color) for concrete seawall panels and lastly, the 15” design to be install for
much wider seawall/bulkheads. The 9” and the 15” displays a scale to install
right at the back side of the seawall/bulkhead. These cylinders slide into the
existing seawall weep holes. The cylinders contain a sliding replaceable filter
cartridge (with a marafi filter weave #SRW300) which is inserted through the
seawall, with the filter fabric flush with the landward side of the seawall. A
special tool is used to insert the filter cartridge and to retrieve the filter cartridge
for replacement purposes.
With the Blue Marlin Filter, the fabric cartridges can be replaced periodically
simply by retrieving the filter cartridge and replacing it with a fresh filter
cartridge. No longer is it needed to bring in heavy equipment, dredging from
behind the seawall, replacing the filter fabric, backfilling the seawall and
replacing the sod and landscape materials. A tremendous savings to the
homeowners.