Navy recovers sunken buoy off Guam
Water spews from a hole in the side of a massive green buoy as it is hauled onto the deck of the USCGC Sequoia. Metal creaks and shudders as the in-hull winch draws up the chain connected to the buoy. A clanging can be heard from the backside of the winch as Petty Officer 3rd Class Peter Ritchel uses a sledge hammer to ensure the wraps of chain are straight and tight on the winch, maximizing space. Under the watchful eye of the crew on the bridge the cutter keeps station off dangerous shoal water at the entrance to Apra Harbor, Guam.
While working buoys is the crew’s bread and butter mission, this is by no means a standard evolution. Apra Outer Harbor Entrance Lighted Buoy No. 1 sank earlier in the month.
“Recovering a sunken buoy is always challenging,” said Lt. Cmdr. William Adams, commanding officer, Sequoia. “We were prepared for and expecting the flooded buoy to weigh about 33,000 lbs. which approaches the 40,000 lbs. working load limit of our crane.
This evolution did not begin with the cutter arriving on scene. The buoy sank near one of the coral reefs on Guam. Often when a buoy sinks cutter crews will drag for the chain to relocate it. That presents two problems. First, it would be damaging to the coral here and requires special approval from NOAA. Second, it puts the crew working the buoy in a challenging position by putting weight at both ends of the chain, the anchor rock on one end and the buoy on the other.
“The availability of divers prevented us from have to use a grapnel hook, a device used to drag the seafloor to recover sunken objects,” said Adams. “Dragging can be slow and tedious, especially when you are not sure of the exact location of the sunken object. You also risk accidentally damaging any coral that might be in the area. The risk of not recovering sunken buoys is they often become entangled in any future aids placed in that assigned position.”
Navy EOD divers from Mobile Unit 5 provided assistance, reducing the evolution’s risk and limiting the impact to the reef by locating the sunken buoy with a remotely operated vehicle eliminating the need to drag for it.
In preparation for working the buoy that morning, the cutter crew inf
As the sun beat down and the humidity set in the small boat approached the site. The cliffs of Orote Point towered in the distance and a small grey vessel loaded with Navy divers and gear bobbed in the swell just off the reef.
“Diver in the water!” calls out the dive master. The Coast Guard crew looked on as a man splashed into the water wearing shorts, fins and a mask. He worked to connect the float bags and put the lift chain in place marking the sunken hull. Both crews were required to back off as the 656-foot roll-on roll-off car carrier Green Lake approached the entrance to the harbor. Its blue hull loomed over the crews as its wake washed past the small boats.
With the chain and float bags in place the small boat crew returned to the cutter and arrived as preparations are made to get underway. The bridge crew deftly navigated away from the pier as an off the dock wind gave them a gentle push. Roughly 30 minutes later they arrived on scene and began the delicate process of coming up on the lift bags and staying clear of the dangerous reef.
“Helmsman, doppler!” calls out Ensign Peter Driscoll, the conning officer. “Point 06 to ahead, point 06 to port,” responds Petty Officer 2nd Class Jennifer Jackson, the helmsman and yeoman aboard.
Doppler measures the speed of the water and current passing the ship. Driscoll used the ship’s thrusters to gently bring the ship alongside the float bags and keep it on station as the deck force hooked them and brought the end of the chain aboard. Using a boat hook a crewman grabbed the line attached to the bags. They quickly hauled it aboard by hand and reaching the end of the chain, hooked it to the in-hull winch and secured the pelican, a sort of clamp and safety holding the chain in place. From there they proceeded to work the buoy.
Several hours later a shiny new green buoy is in place. The old buoy is secured to the deck and water continued to weep from the hole in its hull. Deck force set about clearing the deck and washing it down as the bridge crew navigated back to the dock.
Apra Outer Harbor Entrance Lighted Buoy No. 1 buoy marks the entrance to the main harbor receiving commercial and military traffic into Guam, essential to commerce and national defense. Partnerships, ship handling and planning all came into play to ensure this aid, marking the entrance to a critical commercial port in Guam, was restored.