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July 28-30, 2008
aboard the M/V Spree

An important part of managing and protecting the reefs of Flower Garden Banks National Marine Sanctuary is to maintain the moorings that allow boats to tie up and access the sanctuary.  FGBNMS is a no anchor zone, as designated through our sanctuary regulations, as well as through the International Maritime Organization. 

The National Marine Sanctuary Foundation funded this effort, using funds received from Rowan Companies, Inc., as part of a settlement agreement which included monies designated to restore, protect, preserve, and improve the natural resources of FGBNMS. 


Captains Frank and Melanie Wasson, owners and operators of the M/V SPREE, were contracted by FGBNMS to conduct a cruise to drill new U-bolt locations for mooring buoys at Stetson Bank, and East and West Flower Garden Banks.  Several U-bolts were in disrepair and needed replacement. 

Group photo of the drilling crew on the top deck of the M/V Spree
Back Row L-R: Pete Bryant, Capt. John Camp, Wayne McBee, Kevin Buch, David Snyder, Ian Riddington, Tracy Hamburger, Colm O'Reilly, John Rhodes, Zachary Hileman. Front Row L-R: Kenny Cruise, Gregg Tatum, G.P. Schmahl, Capt. Frank Wasson, Melanie Wasson.
Photo: Hickerson/FGBNMS

The following team of experienced divers was assembled by Frank and Mel:

Kevin Buch
Kenny Cruise
Zachary Hileman
Wayne McBee
John Rhodes
Ian Riddington
David Snyder
Gregg Tatum

Steve Harbin and Mel kept us well fed.

Flower Garden Banks participants were on hand to advise and observe:

G.P. Schmahl – Sanctuary Superintendent
Emma Hickerson – Research Coordinator
Tracy Hamburger – Marine Operations Officer

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U-Bolt Replacement

A hydraulic drilling rig owned by FGBNMS was used to conduct the work.  The hydraulic pump sat on the stern deck of the M/V Spree during operations.  Hydraulic hoses ran forward to the bow, and over the side. 

Large drill standing upright in a whole on the sea floor.  Two stacks of lead weights and a metal, u-shaped rod rest on the rocks nearby.
Hydraulic drill rig sitting in one of a pair of holes drilled into dead coral at West Flower Garden Bank for Buoy #3. The new U-bolt sits in the background next to the old U-bolt, which has been twisted and broken. Coral cores which have been removed during the drilling process are also visible. The weight belts are used by the drillers to provide extra downward weight during the drilling process.
Photo: Hickerson/FGBNMS

A specially fabricated drill bit with large teeth was used for Stetson Bank due to the nature of the claystone.  A diamond tipped drill bit was used for the drilling at East and West Flower Garden Banks.  The drill bits are about 4 inches in diameter.

Divers were deployed off the bow, carrying the drill and bits to the target location.  Teams were deployed in 20 minute shifts during the drilling.

Two divers, one on each side, pushing the hydraulic drill into the rock at Stetson Bank.
Frank Wasson (right) and David Snyder (left) drilling at Stetson Bank for Buoy #2. The specialized drill bit can be seen in the foreground.
Photo: Hickerson/FGBNMS

Paired U-bolt holes, approximately 6 feet in length, were drilled into the claystone at Stetson Bank Buoy #2, and into dead coral heads at West Flower Garden Bank #5 and #3, and East Flower Garden Bank #2, at sites selected by sanctuary staff.

After the paired holes were drilled, cement was premixed and loaded up into long PVC tubes, which were carried down by divers.  The tubes were uncapped, and cement was poured into the holes around the U-bolt which had been placed into the drilled holes.

A diver holding a long, white PVC tube in a vertical position over a hole in the sea floor.  Cement flows down the tube into the hole.
A queen parrotfish supervises Tracy Hamburger as she pours cement around a newly placed U-bolt at West Flower Garden Bank.
Photo: Hickerson/FGBNMS

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General Observations

Sea conditions were reasonable, sea surface temperatures were about 84F, and there was relatively little current.  There was good visibility at all banks. 

A whale shark (about 20 feet in length) cruised by the boat at Stetson Bank on July 28, but was only seen from the deck…unfortunately the divers doing their safety stop were looking the wrong direction! 

A loggerhead sea turtle was observed taking a breather on the surface at Stetson Bank.  Several small dusky sharks were also noted by divers.  Two manta rays visited G.P. and Tracy on their reconnaissance dive at East Flower Garden Bank. 

Emma Hickerson photo and video documented the activities.

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Thanks go to the terrific drilling team, as well as the Captains and crew of the Mighty M/V SPREE!

Thanks also go to the National Marine Sanctuary Foundation (NMSF) for managing the funds awarded through the Rowan settlement.

Download the Mooring Drilling Cruise Report (416kb pdf)

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weather report observations cool stuff get wet

Orange, branching gorgonian (soft coral) anchored in a bed of sponges and other sea life.
National Marine Sanctuary logo - a stylized whale tail above waves