German frigate Hessen sailors were on watch 12 hours a day in the Red Sea with only seconds to react to threats in the 'worst case scenario'

• A German warship that was part of a European Union security mission has left the Red Sea.
• The frigate Hessen spent weeks in the Middle East protecting commercial ships from Houthi attacks.
• Its sailors were on watch for 12 hours a day, Germany's military said on Monday.

Sailors aboard a German warship that was recently deployed to the Red Sea were on watch for 12 hours a day, and in the "worst" situations, they might've only had seconds to respond to the deadly Houthi threats endangering ships in these waters.

The Hessen, a Sachsen-class frigate, left the Red Sea and entered the Suez Canal on Saturday after spending nearly 60 days operating in Middle Eastern waters, Germany's military said Monday.

The warship was deployed to the region as part of the European Union's Operation Aspides security mission, which has been tasked with protecting commercial vessels sailing off the coast of Yemen from unrelenting Houthi missile and drone attacks.

Around 240 crew members aboard the Hessen were on "a permanent war march" during the mission, the German military said in a statement, according to a translation. These sailors were on guard for six hours, then had six hours off, and then went back on guard for another six hours.

"This very high state of readiness was due to the constant three-dimensional threat" that the Houthis posed to the ships in the area, the German military said. "In the worst case scenario, the ship and crew would only have had about ten seconds to bring their own defensive weapons into effect."

The short timeframe underscores how fast some of the Houthi threats are. One sailor aboard a US Navy warship that has engaged the rebels told Business Insider during a visit to the Red Sea earlier this year that their response time to an inbound threat could be anywhere from minutes to just seconds.

Throughout its time in the area of operations, which included the strategic Red Sea, Gulf of Aden, and Bab el-Mandeb Strait, the Hessen repelled four Houthi attacks and escorted more than two dozen commercial ships through the volatile waters, Germany said.

In one noteworthy kill last month, a helicopter attached to the warship destroyed a Houthi surface drone after it was identified as a threat to civilian ships.

"This mission has demanded more from the ship and crew than ever before," the Hessen's Capt. Volker Kübsch said, adding that his warship "worked like clockwork and impressively demonstrated its combat value — right down to its ability to prevail in battle."

"Especially in combat situations, we were able to gain valuable, even unique experience not only for ourselves, but also for the entire German Navy and beyond," Kübsch added, highlighting how these engagements are a learning opportunity and a chance to test and improve capabilities. US Navy commanders have expressed similar thoughts on intercepts of anti-ship ballistic missiles.

While the Hessen's presence ultimately proved to be a valuable asset for the EU security mission, there was an incident at one point during the warship's deployment involving an allied asset.

In late-February, the Hessen accidentally targeted a US MQ-9 Reaper drone that was operating around the Red Sea and fired several missiles at the aircraft. A technical error in the warship's radar system, however, spared the American combat drone.

The Hessen is one of several European warships to see combat in the Red Sea this year, alongside the US Navy, which has had an aircraft carrier and multiple other warships stationed in the region since last fall. Beyond intercepting Houthi missiles and drones in the air, American forces, sometimes with partners, have also struck the rebels on the ground in Yemen.

The Hessen is due back to the German port city of Wilhelmshaven in early May. The gap it left in Operation Aspides is expected to be filled in early August by the Sachsen-class frigate Hamburg, Germany said.