The U.S. Coast Guard is facing a growing threat in the Caribbean: undersea drug trafficking.

The New York Times recently recounted an incident where the sea service interdicted an illegal semisubmersible vessel smuggling cocaine from Colombia. U.S. security forces have long combated smugglers bringing drugs and other contraband into the country via the Gulf; however, semisubmersible and fully submerged vessels are emerging as a preferred means of transportation for these shipments, as it improves the smugglers’ chances of going undetected.

In the most recent run-in with these illegal vessels, the Coast Guard Cutter Mohawk utilized an interagency intelligence effort to locate the submersible and then pursued it with its deck-launched helicopter and fast boat. Though the smugglers were able to sink their vessel before the Coast Guard could salvage most of their cargo, this effort is considered a success both for the joint preparatory work performed in locating the smugglers and the proficiency the Mohawk crew showed in executing their interdiction mission.

While the Coast Guard has successfully performed many similar operations, the sea service’s role in the Caribbean and elsewhere will be increasingly burdened by an aging and shrinking fleet. The Mohawk is the newest of the Famous-class medium endurance cutters, commissioned in 1991. Many in this class are reaching their 30-year service lives and will likely require extensions to fill mission gaps. According to the Government Accountability Office, the Coast Guard’s high and medium endurance cutters have been falling below performance expectations for a number of years. The bottom line is these vessels need replacement.

Yet the Obama Administration is taking action to undermine this overhaul rather than accelerate it. The Offshore Patrol Cutter—the Coast Guard’s intended replacement for both the Famous fleet and the Reliance-class Medium Endurance Cutters—is currently in limbo due to recent budget uncertainty. The National Security Cutter, the replacement for the extremely old Hamilton-class High Endurance Cutter, will shrink to a fleet of just six vessels under the President’s Fiscal Year 2013 budget request, well below the original requirement of 16.

These vessels patrol the Pacific and Arctic, not just the Caribbean and other coastal waters of the Continental United States. The Coast Guard’s fleet size is not keeping up with increased demand, and legacy vessels will continue to be overtaxed as a result.

If Congress does not act to correct the chronic underfunding of the Coast Guard’s fleet revitalization, the sea service must continue to operate in aging craft. As they require increasing maintenance with age and mileage, these vessels will continue to incur greater costs for maintenance and repair, thus steering resources away from the more capable replacements that the Coast Guard needs. One can see the downward spiral this creates.

While the Coast Guard continues to perform its missions admirably, they will find it increasingly difficult to keep up the pace with insufficient resources and equipment. Congress, in fulfilling its constitutional responsibility to provide for the common defense, should make a commitment to the Coast Guard to protect America’s seas and waterways.