WILLIAM BRANGHAM: Tonight, we give you# an inside look into one of Ukraine's## most rapidly evolving tools in its war with# Russia, drones.

These small unmanned machines## have come to dominate the battlefield from the# front line in the east to long-range strikes## against power facilities to the waters# of the Black and Mediterranean Seas.

Special correspondent Volodymyr# Solohub gained rare access to a## military unit that is responsible for some# of Ukraine's highest-profile drone strikes.

And a note, we allowed them to review some of# our footage before it aired for security reasons.

VOLODYMYR SOLOHUB: On a river outside of# Kyiv, Ukraine's Defense Intelligence is## taking us to one of their most prized weapons.# They have helped push Russia's fleet away from## occupied Crimea, disrupted supply lines,# and changed the balance of power at sea,## naval drones operated by a unit# known as Group 13, Magura 5,## a kamikaze boat.

Magura 7 outfitted with American# missiles, inventing new weapons out of necessity.

Ukraine doesn't have its own navy.# When Russia annexed Crimea in 2014,## Ukraine lost almost all of its navy.

So,# when the new invasion in 2022 started,## Ukraine had to rely on unmanned naval drones like# these to fight a more powerful and much better## equipped enemy.

They're fast, effective, difficult# to detect, and has caused Russia a lot of trouble.

Just last week, in a highly produced video,# Ukraine showed off how its naval drone struck## a Russian submarine.

That helps keep the# Western Black Sea open to Ukraine experts,## and forces Russia's ships to dock in# Novorossiysk in their own territory,## well east of the occupied Crimean Peninsula.

Group 13's commander, who we promised to keep# anonymous, explains his unit's core mission.

GROUP 13 UNIT COMMANDER, Ukrainian# Defense Intelligence (through translator):## Little by little, we pushed the most active# and most dangerous part of Russia's Black## Sea fleet off the western part of the# Black Sea.

Right now, Russians do not## keep anything that is valuable or important# in Crimea.

Everything is in Novorossiysk.

VOLODYMYR SOLOHUB: But even in Novorossiysk,## Russia's fleet is not safe.

From summer# of 2023 to the spring of 2024, Ukrainian## naval drones pummeled Russian ships hundreds# of miles from Ukraine-controlled territory,## including the patrol ship Sergey Kotov,# which Ukraine said was worth $65 million.

It's an example of Ukraine using relatively cheap# weapons to take down expensive Russian hardware.

GROUP 13 UNIT COMMANDER (through# translator): In our missions,## we work in flocks if we're talking# .. during the mission on Kotov, we were# working in flocks and were hunting it.## The ship was trying to hide between the commercial# vessels and escape near the Crimea Bridge.

VOLODYMYR SOLOHUB: Group 13 even uses drones# to strike Russian helicopters.

But, recently,## Ukraine's tactics have shifted.

The drones are# now striking Russia's so-called shadow fleet,## the oil tankers Russia uses to# evade sanctions and finance the war.

And Ukraine's drone targets aren't only military.# Kyiv believes that one way to pressure Putin is to## bring the war home to everyday Russians.

Ukraine's# built an army of long-range drones that have also## targeted Russia's economic lifeblood, energy# facilities, some as far as 600 miles away.

At one point this year, long-range Ukrainian# drones took down more than 10 percent of## Russia's refinery capacity.

Just last# week, long-range aerial drones struck## a Russian tanker in the Mediterranean# Sea, 1,200 miles from Ukraine's border.

Inside an unmarked hangar, the Beaver# is a 200-pound kamikaze drone capable of## traveling up to 600 miles.

This commander# also asked us to keep him anonymous.

UNIT COMMANDER, Ukrainian Defense Intelligence# (through translator): With our deep strikes,## we're targeting Russian fuel bases, logistics# hubs.. them to move all of this away from the front# line.

And thus their logistics take more time.

VOLODYMYR SOLOHUB: But Russia is# way ahead of Ukraine with its own## deep strikes.

Over the last week alone,# Moscow launched an average of 726 drones,## mostly at energy and infrastructure targets.

And Russia's ability to manufacture drones# exceeds Ukraine's.

At this factory shown on## Russian TV earlier this year, workers claimed# they manufactured more than 400 per day.

But,## at sea, Ukrainians are still on the offensive.

GROUP 13 UNIT COMMANDER (through# translator): We're fighting for our survival.

We have no choice but to fight.

VOLODYMYR SOLOHUB: As the war continues,## unmanned systems are reshaping the battlefield.# And as both sides brace for what co.. Ukraine's unmanned army is now an# increasingly central part of the fight.

For the "PBS News Hour," I'm# Volodymyr Solohub in Kyiv, Ukraine.