Once upon a time, Ukraine had a Navy. Then Russia stole it.

On February 27, 2014, unidentified gunmen stormed the parliament building in Ukrainian Crimea, initiating a chain of events that culminated in Russia's annexing the Crimea three weeks later. Along the way, Russian forces seized millions of dollars worth of Ukrainian military equipment based in Crimea, including the bulk of the Ukrainian navy.

While Russia says it has since repatriated many of Ukraine's smaller vessels, what remains of the Ukrainian navy today is a pretty sad bunch of boats. Aside from a handful of corvettes and missile boats useful mostly for coastal patrol, Ukraine's only significant warship is its flagship, the frigate Hetman Sahaydachniy.

Ukraine wants to change that.

In April 2015, Ukrainian President Petro Poroshenko declared Ukraine's desire to build a "modern, high-tech" navy that can "easily work with NATO member countries" to patrol the Black Sea. That's a mission that's become urgent in the past couple years, as Russia has become increasingly aggressive in the area, and Syrian refugee migration via Turkey has increased.

More recently, in a discussion with deputy commander of U.S. Naval Forces Europe Vice Adm. James Foggo , Ukrainian Prime Minister Arseniy Yatsenyuk discussed his desire to upgrade the Ukrainian navy with new warships. Just last week, Ukrainian Vice Adm. Sergey Hayduk confirmed Ukraine's intention to sell a 25-year-old hulk, the unfinished cruiser Ukraina, to raise funds to buy two newer, smaller, more modern warships.

Which raises two questions: Who will build these boats -- and can Ukraine afford them?

Round up the usual suspects

Wanting warships is one thing. Paying for them is another. A modern corvette, the smallest "rated" warship class -- costs roughly $125 million. Frigates -- the next class up -- cost three to four times that (about $400 million to $500 million ), while a modern guided missile destroyer can cost three to four times that ($1.5 billion).

But at last report, Ukraine is budgeting just $5.7 billion for annual defense spending. That probably puts destroyers out of its price range, and it makes buying even a new frigate a stretch. Once you get down to the corvette level, though, that's something Ukraine could probably afford.

Round up some unusual suspects

Assuming Ukraine intends to buy these boats from the U.S. (reasonable, given its discussing the plans with U.S. officials), we thought a short survey of likely shipbuilders might be in order. The two largest U.S. military shipbuilders, Huntington Ingalls (NYSE:HII) and General Dynamics (NYSE:GD), don't really "do" small warships, though. Huntington's National Security Cutter, for example, measures 418 feet stem to stern and costs nearly $700 million. A General Dynamics-built Zumwalt-class destroyer runs to 600 feet in length and costs more than half of Ukraine's annual defense budget.

But here are a few privately owned ship builders who might help out.

Bollinger Shipyards

A major builder of Coast Guard and Navy vessels, including Cyclone-class patrol boats, Lockport, La.-based Bollinger does $227 million in annual business, according to data from S&P Capital IQ. That doesn't put it in nearly the same league as General Dynamics or Huntington Ingalls. But Bollinger is experienced at building ocean-going warships up to 170' in length. That's just about the right size for a corvette. Bollinger is also competing to build the U.S. Coast Guard's new Offshore Patrol Cutter (OPC), a vessel likely to exceed 200' in length.

Eastern Shipbuilding Group

Like Bollinger, Eastern Shipbuilding is in the running to build the OPC. The Panama City, Fla.-based builder is bigger than Bollinger, with $338 million in annual revenue. It's also been known to build even bigger boats -- as much as 302' in length, a size approaching that of smaller frigates.

Metal Shark

Yet another builder of boats for the Coast Guard and military, Franklin, La.-based Metal Shark inked a deal to supply five 75-foot fast patrol boats to the Vietnamese navy this year. Those cost only $3.6 million apiece, putting them well within Ukraine's budget. And should Ukraine opt for larger vessels, Metal Shark has standard designs for corvette-sized vessels -- 165 feet -- and an avowed ability to build warships as big as 250' in length.

Maritime Security Strategies / RiverHawk Fast Sea Frames

Two shipbuilders so secretive they don't even maintain active websites, Maritime Security Strategies and RiverHawk Fast Sea Frames work mainly through contract manufacturers. In 2012, the companies delivered to Lebanon a 138' "Advanced Multimission Platform" warship (pictured above) that's been described as "cost-effective" at a price of just $29 million. In 2011, the companies sold a pair of 180' armed Offshore Support Vessels to the Iraqi navy -- at just $35 million apiece.

SAFE Boats International

Builders of military boats drop rapidly in size from there. Bremerton, Washington's SAFE Boats is one such builder. It produces riverine patrol and command boats for the Navy, including the 85-foot Mk VI Patrol Boat.

U.S. Marine

U.S. Marine out of Gulfport, Miss., builds the similar Mk V patrol boat, 90' long, and its twin 82' MK V "SOC" for U.S. Special Forces Command.

Oregon Iron Works

Clackamas-based Oregon Iron Works may not sound like an idea worth floating, but it in 2014, SOCOM downselected Oregon Iron to build its newest special operations watercraft, the "Combatant Craft, Medium Mark 1."

Willard Marine

At $20 million in annual revenue, Anaheim, Calif.-based Willard Marine focuses on small boats, but it has been known to go as big as 55 feet. Willard is also the only company on this list known to count the Ukrainians as customers already. It recently delivered five rigid inflatable boats to Ukraine's military.

Juliet Marine Systems

Last but not least in our survey is the dark horse of the pack, Juliet Marine. Juliet has yet to win a contract from... anyone that we know of. But the company's groundbreaking "Ghost" patrol boat is a 38-foot, 50 mph, missile-armed "attack helicopter of the sea," and it has won praise in the military press. Potentially, Juliet could give Ukraine a good price in hopes of winning its first sale.

A word for investors

To reiterate, all of the small shipbuilders named above are privately owned. You cannot invest in any of them. (At least not yet. One high-profile contract win could be enough to entice a larger defense contractor to snap one of these companies up, or tip the scales in favor of an IPO.)

Absent those eventualities, the "traditional" defense contractor most likely to take an interest in building warships of a size Ukraine can afford is Huntington Ingalls. Although Huntington doesn't build small warships today, it used to build corvette-sized "Eilat-class" vessels for the Israeli navy in the 1990s.

What's more, Huntington lost a bid to build the Offshore Patrol Cutter last year, costing it a big source of potential income. Necessity, and international customer demand for smaller warships, may dictate that Huntington take a look downmarket for revenues to replace those lost with the OPC contract. Ukraine's desire to upgrade its navy could be the catalyst that pulls Huntington Ingalls back into this marketplace.