(NewsNation) — As a record number of migrants attempt to cross the U.S.-Mexico border by land, authorities in Florida are dealing with an influx of migrants coming by sea.

Earlier this month, Gov. Ron DeSantis signed an executive order activating the Florida National Guard to help manage the influx of migrants landing in the Florida Keys.

Most of those migrants are coming from Cuba and Haiti and at least 65 have died at sea since August. In total, more than 4,400 migrants have arrived by boat in Florida over the past five months.

NewsNation joined border agents in Marathon, Florida, to see firsthand how authorities are managing the crisis.

Over the course of the day, federal agents took NewsNation around some of the popular landing spots for illegal migrants, many of which are public beaches.

In some areas, makeshift boats line the shores. One abandoned vessel is scattered with clothes and shoes — now artifacts of a perilous journey.

Just steps away, there’s another boat that agents say has been stuck for a couple of weeks. It carried about 20 migrants when it hit the shore.

Authorities say moving the boats has become an expensive, labor-intensive process.

“They’re not functional, you can’t drive them to a boat ramp and put them on a trailer,” said Adam Hoffner, division chief for U.S. Customs and Border Protection’s Miami operations. “Essentially they have to be disposed of.”

Last year, Monroe County — which includes the Florida Keys — spent more than $93,000 on vessel removals. Officials say migrant vessels accounted for more than 67% of that total.

Even with the removals, the exact number of migrant and derelict vessels in the Florida Keys is unknown.

Less than two weeks ago, the U.S. Coast Guard intercepted a sailboat crammed with 70 Cuban and Haitian migrants. The Coast Guard said migrant encounters in its Miami sector are up 400% since October.

Despite the recent uptick, Hoffner says the illegal crossings aren’t new but have become part of a broader, concerning trend.

“This has not been an overnight surge, this has been relatively ongoing for some time,” he said.

That reality has forced CBP to send additional resources to the region.

When migrants do make landfall, agents say it can take up to an hour to process a single person. Spread that across several hundred simultaneous arrivals and this becomes a significant resource challenge.

But relief may be coming.

Earlier this month, the Biden administration said it would immediately begin turning away Cubans, Haitians and Nicaraguans who cross the U.S.-Mexico border illegally. It remains to be seen what impact that will have on migrants who arrive in Florida.

The effect of Biden’s announcement will become more clear when January’s border encounter numbers are released next month.