New satellite imagery shows that Iran has quietly deployed drones and submarines on its southern coast. It’s a sign that the Islamic Republic is expanding its naval power and looking to push American warships farther off its shores.

The satellite images, published this week by Google Earth, indicate the presence of surveillance drones and Ghadir midget submarines at Bandar-e Jask, an Iranian naval base just southeast of the strategically crucial Strait of Hormuz. The facility’s use as a drone and submarine base has not been previously reported.

Over the past few months, Iran’s military has been active on a variety of fronts across the region, supporting the Bashar al-Assad’s regime’s bloody crackdown against rebels in Syria, helping the Iraqi government and Shiite militias face off against Islamic State jihadists, in Iraq and reportedly providing limited support to Houthi rebels in Yemen.

Iran’s deployment of drones and mini-subs likely has more to do with deterring any future American attacks than launching offensives of their own. But it illustrates how the Islamic Republic’s armed forces are trying to operate farther outside their historic comfort zones.

“They’ve been trying to focus on taking where the U.S. feels comfortable operating and pushing that further and further out,” said Matthew McInnis, a resident fellow at the American Enterprise Institute and former senior Middle East analyst at U.S. Central Command. “They want to get it as far out into the Arabian Sea as they can so the U.S. cannot operate close in.”

The Mohajer series of drones, made by Iran’s Ghods Aviation, are unarmed surveillance aircraft used over the conflicts in Iraq and Syria. In January, Digitalglobe imaging satellites caught a glimpse of a Mohajer-4 drone attached to a rail launcher—the unmanned aerial vehicle can launch from a rail by rocket-assisted takeoff—by the side of the runway at a naval base in Jask. The Mohajer-4’s distinctive truck-mounted ground control station is visible on the other side of the runway and is identifiable by its circular white antenna.

The January imagery update from Google Earth also shows the presence of a Ghadir mini-submarine at Jask. The Ghadir is widely believed to be based on the North Korean Yono class mini sub, which was reportedly used to sink the Cheonan, a 1,200-ton South Korean Navy corvette, in March of 2010. Although little is known about the Iranian subs, photos suggest they can fire torpedoes and carry naval mines.

Other commercial satellite imagery from 2014, reviewed by The Daily Beast, shows UAV rail launchers repeatedly placed near the runway at Jask and between one and three Ghadir coastal submarines deployed to the base.

Iran’s use of surveillance drones dates back to the Iran-Iraq war of the 1980s, when Iranian forces developed and used the Mohajer-1, the forerunner of the UAV seen at Jask, to spy on Saddam Hussein’s forces. But Iran’s interest in unmanned aviation, a mixture of chest-thumping me-too-ism and legitimate military interest, has increased significantly over the past decade. Iran’s UAVs have severe limitations compared to their more capable counterparts in Western militaries, including a lack of beyond line of sight communications and a claimed but largely unproven ability to fire air-to-ground missile. Nonetheless, they have found a niche market helping Iran’s allies in Baghdad and Damascus prosecute their wars.

The Persian Gulf and the Strait of Hormuz in particular have been the centerpiece of Iranian naval thinking for years. The Strait, just 21 miles at its narrowest point, is a critical strategic choke point through which nearly a third of the world’s seaborne oil trade flows, according the U.S. Energy Information Agency.

Closing it would wreak havoc on international energy markets and limit the ability of Iran’s Arab adversaries across the Gulf to ship their most valuable export. And so Iran has built swarms of armed fastboats—and a similar deployment of drones and Ghadir subs—to make that threat credible in the event of a conflict with the United States.

But the investment in building up Jask and other locations along Iran’s southern coast is a sign that Iran’s naval strategy is placing more emphasis on areas outside the Persian Gulf.

Iran’s military forces are divided between the more ideological Islamic Revolutionary Guard Corps (IRGC) and the forces of Artesh, the holdover of Iran’s pre-revolution professional military. In 2007, Iran reorganized the geographic division of labor for the two forces, giving primary responsibility for the Gulf of Oman and Arabian Sea to the Artesh’s Islamic Republic of Iran Navy (IRIN) and handing the naval arm of the IRGC the lead in the Persian Gulf.

The move placed Jask as the headquarters for IRIN’s second naval district, a location which its commander Admiral Habibollah Sayyari said would help in “preventing the entry of any kind of enemy into the strategic Persian Gulf” when the base was opened in 2008.

Since that time, IRIN has been busy at Jask, conducting a string of military exercises and building up its basing infrastructure, including a new hangar, helipad and protective harbor.

Other IRIN facilities along the southern coast have also seen increased activity. Less than 150 nautical miles east of Jask, the Konarak naval base has hosted Ghadir deployments for exercises as well as other support vessels like the German-built Bander Abbas and Pakistan-built Delvar class boats. In fact, imagery has shown the support vessels consistently deployed to the area since 2013—another indicator of Iran’s intent to push operations into the Sea of Oman.

Further toward the Pakistani border, IRIN opened a new naval base at Pasabandar in October 2014—though no significant support infrastructure or vessels are visible in imagery.

Surveillance drones and midget submarines, alone though, aren’t enough to keep the U.S. Navy far off Iran coastline.

Instead, Iran is hoping that its growing arsenal of anti-ship cruise missiles, mostly derived from Chinese technology and licensed production, can stiff-arm American warships. In February, Iran showed off some of the missiles in the theatrical destruction of a mockup of an American aircraft carrier off Bandar Abbas. Closer to Jask, Iran tested a Qader anti-ship cruise missile during the January 2013 Velayat-91 exercises.

Ultimately, Iran’s strategy is more about altering America’s marginal risk calculus than outright defeating its military power, McInnis said.

“The U.S. has all sorts of standoff capacity to hit Iran from quite far away,” he added. “This certainly doesn’t eliminate the [American] threat, but it creates a situation where the U.S. ability to protect its own assets in the Gulf becomes increasingly problematic.”

While the U.S. and Iran have experienced something of a thaw in their relationship lately—thanks to direct talks over the future of Iran’s nuclear program and the U.S. military’s accommodation of Iranian proxies fighting ISIS in Iraq—mutual suspicion and wariness still runs deep.

The U.S. and Iran are backing different parties in the fight to control Syria and Yemen. Tension between America’s allies in the Middle East and Iran’s proxies still runs high. And the the two sides are still involved in a game of cyber-espionage and online counterattack. The memory of the 1988’s Operation Praying Mantis, when the U.S. and Iran fought a very brief, miniature war over Iran’s mining of the Persian Gulf, also still looms large in the memories of both countries’ naval strategists. In short, neither the U.S. or Iran is likely to drop its guard anytime soon.

But Iran’s naval activity is also driven by a recognition of the growing economic importance of its southern coast, which Admiral Sayyari has labeled the country’s “golden gate.” Iranian officials have repeatedly stated that they intend to transform Jask into a free trade zone and the country’s second-largest oil terminal next to Kharg Island in the Persian Gulf. With financial assistance from China announced in January, Iran plans to build an industrial park at the port city, developing the petrochemical, refining, aluminum, and steel sectors.

If conflict did erupt in the Strait, Jask would become a vital secondary port to keep exports flowing, especially oil. Even with sanctions, Iran’s government revenue is still heavily dependent on the export of oil, accounting for 40 percent of revenue, down from 70 percent before the international community stepped up pressure in 2012.

The satellite imagery of the drone base only provides brief glimpses of the economic and military investment along its southern shores. But the pattern of activity demonstrates a clear recognition of the region’s importance to Iran, meaning there’s likely to be more developments on the Makran coast—both seen and unseen.