NVIC 10-91: Inspection of floating detention facilities

Last reviewed: October 14, 2026

This Circular gives guidance on the construction, operation, and Coast Guard inspection of non-self-propelled floating detention facilities. On request from a state or local municipality, the Coast Guard will inspect and certify a facility under 46 C.F.R. Subchapter H if it is otherwise not subject to inspection. Permanently moored facilities may be designated "substantially a land structure".

Applies toThe Circular applies to U.S. flag vessels and to foreign flag vessels in U.S. waters, including new construction and existing vessels converted to detention facilities.

What it says

  1. On request from a state or local municipality, the Coast Guard will inspect and certify a floating detention facility under 46 C.F.R. Subchapter H if the facility is otherwise not subject to inspection.

    NVIC 10-91 4.b“Upon request from a state or local municipality, the Coast Guard will provide inspection and certification under the provisions of 46 C. F.R. Subchapter H for a floating detention facility that is, otherwise, not subject to inspection.”
  2. Enclosure (1) should be used as a guide in applying these regulations.

    NVIC 10-91 4.b“Enclosure (1) to this Circular should be used as a guide in applying these regulations.”
  3. Except as discussed in paragraphs 4.e and 4.f, floating detention facilities that carry "passengers for hire" must be inspected as passenger vessels.

    NVIC 10-91 4.c“Except as discussed in paragraphs 4.e and 4.f, floating detention facilities engaged in the carriage of "passengers for hire" are subject to and shall be inspected as passenger vessels.”
  4. The Circular applies to new construction and to existing vessels converted to detention facilities. For converted vessels, the provisions are applied insofar as is reasonable and practicable.

    NVIC 10-91 4.d“For converted vessels, these provisions will be applied insofar as is reasonable and practicable.”
  5. A foreign flag floating detention facility must have a Coast Guard Certificate of Inspection (COI) unless it is designated "substantially a land structure".

    NVIC 10-91 4.e“A foreign flag floating detention facility, unless designated "substantially a land structure," must have a Coast Guard Certificate of Inspection (COI).”
  6. Inspection certificates issued by another administration will not be recognized.

    NVIC 10-91 4.e“Inspection certificates issued by another administration will not be recognized.”
  7. On request, a permanently moored floating detention facility that is taken out of navigation will be designated "substantially a land structure" and will not be subject to the inspection laws of 46 U.S.C.

    NVIC 10-91 4.f“A floating detention facility which is permanently moored and thus taken out of navigation, will, upon request, be designated "substantially a land structure"”

Common questions

Does a foreign flag floating detention facility need a Coast Guard Certificate of Inspection?

Yes, unless it is designated "substantially a land structure". Inspection certificates issued by another administration will not be recognized.

“A foreign flag floating detention facility, unless designated "substantially a land structure," must have a Coast Guard Certificate of Inspection (COI).”

Is a vessel designated "substantially a land structure" free of all regulation?

No. It is not considered a vessel for inspection purposes, but it remains subject to other regulations, such as those promulgated under the Ports and Waterways Safety Act.

“A vessel designated "substantially a land structure" is not considered a vessel for inspection purposes, however, it remains subject to the other regulations”

Do the NVIC 10-91 provisions apply to converted vessels?

Yes. They apply to new construction and to existing vessels converted to detention facilities, applied insofar as is reasonable and practicable for converted vessels.

“The provisions of this Circular are to be applied not only to new construction, but also to existing vessels converted to detention facilities.”

The text of NVIC 10-91

U.S. Coast Guard, NVIC 10-91 (main body; enclosures not shown)

Inspection and Certification of Floating Detention Facilities

NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 10-91 Electronic Version for Distribution Via the World Wide Web Subj: Inspection and Certification of Floating Detention Facilities Ref: (a) NVIC No. 10-82, "Acceptance of Plan Review and Inspection Tasks Performed by the American Bureau of Shipping (ABS) for New Construction or Major Modification of U.S. Flag Vessels" (b) NVIC No. 8-84, "Recommendations for the Submittal of Merchant Vessel Plans and Specifications"

Inspection and Certification of Floating Detention Facilities — PURPOSE. This Circular provides information to vessel designers, owners, operators, shipyards,

and municipal officials, as well as Officers in Charge, Marine Inspection (OCMI) concerning the construction, operation, and Coast Guard inspection of non-self-propelled floating detention facilities.

Inspection and Certification of Floating Detention Facilities — BACKGROUND.

a. During recent years, large municipalities have found that the number of land-based prisons and detention facilities is insufficient to properly accommodate the high numbers of prisoners being incarcerated and detainees awaiting arraignment. This has become particularly acute with the escalating "war on drugs." Increasingly, judges and other officials have ordered prison officials to relieve prison overcrowding. This often results in the early release of prisoners. One alternative, apparently quicker than increasing the number of land-based prisons, is to use accommodation barges to house prisoners and detainees. Some of these barges are specially designed and built, while others are converted from vessels of other uses. b. Traditionally, prisons have been built ashore and the Coast Guard has had no involvement in their construction or their operation. In 1987, the city of New York was tasked with creating an additional 100 prison beds per month due to the crackdown on drugs. It decided to use two surplus Staten Island ferries to house minimum security prisoners. These vessels had been Coast Guard inspected passenger vessels. The city requested that the Coast Guard continue certification while the ferries were used for their new purpose. Even though these vessels were not specifically designed as prisons, with some security modification, they were able to be brought on line very quickly, relatively speaking, so the city could comply with the courts' requirement to adequately house the prisoners at Rikers Island in New York Harbor. c. Considering their use for minimum security prisoners, the OCMI inspected these vessels giving consideration to their use only while moored. At that time, this was viewed to be a local short-term solution to the prison overcrowding situation. The city also leased a foreign flag accommodation barge for this purpose, for which inspection was not requested, nor was it provided. NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 10-91 d. In 1989, the city approached the Coast Guard with a request for the inspection and certification of a new 800-bed maximum security floating detention facility. At this point, it became apparent that the floating alternative to the traditional land-based prison facility might have national, if not international, application.

Inspection and Certification of Floating Detention Facilities — DISCUSSION.

a.

Historically, owners of other substantially moored vessels, such as floating restaurants or floating museums, have sought to avoid Coast Guard regulation by having their vessels considered permanently moored and designated "substantially land structures." However, some owners have noted advantages in retaining the vessel status.

When a vessel retains vessel status, and performs a service for which inspection is required (e.g., carries passengers for hire), Coast Guard inspection and certification is mandatory under Title 46, United States Code (46 U.S.C.) - Shipping.

Generally, if a vessel is engaged in a service for which inspection is not required by law, it will not be inspected except as may be specifically agreed to on a case-by-case basis. b.

In most large metropolitan areas, crime is on the increase. prison overcrowding is a continuing problem.

The construction of more prison space is obviously a more favored alternative than the possible release of prisoners where adequate facilities cannot be provided. c.

The Coast Guard expends a tremendous amount of material and effort in surveillance and interdiction of illegal drug activities.

The marine inspection program can directly support this primary mission area by assisting in the effort to produce adequate detention facilities, specifically those which are vessels, to effectively incarcerate drug offenders. d.

Construction time for facilities ashore is estimated at five to seven years depending on the controversy over the sitting, rules, and approval procedures of the cognizant municipality.

Construction of a floating facility can be accomplished by a shipyard in approximately two years.

Further, U.S. shipyards have the capacity and can perform the construction needed to provide these facilities. e.

Floating detention facilities will clearly exceed 100 gross tons.

Due to the large number of persons on board these vessels, it is appropriate to apply standards equivalent to those applicable to passenger vessels under Title 46, Code of Federal Regulations (46 C.F.R.), Subchapter H.

However, the Coast Guard's regulations for passenger vessels, as well as the international standards, were not written with such vessels in mind.

The basic Coast Guard and International Maritime Organization philosophy for the protection and escape of passengers and crew is very different from that of a maximum security prison.

Thus, the Coast Guard's passenger vessel regulations cannot be fully applied. f.

The application of certain American Bureau of Shipping (ABS) Rules and shore-based building requirements is appropriate to establish an equivalent level of safety to that of a passenger vessel, i.e., provide ample protection in the case of an emergency and an efficient means of emergency egress if necessary.

ABS recently published preliminary rules for floating accommodation and hotel barges.

Designers for shore-based prison facilities are guided by the National Fire Protection Association (NFPA) Life Safety Code for Detention and Correctional Facilities.

NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 10-91 g.

The owner (or bareboat charterer) of a floating detention facility is likely to be the state or local municipality.

Although compared to passenger vessels, these facilities are not engaged in the carriage of “passengers for hire” because it is not likely that valuable consideration will flow directly or indirectly to the owner, charterer, operator, agent or any other person interested in the vessel (46 C.F.R. 70.10-3).

However, where such consideration does exist, e.g., a privately owned accommodation barge for which the municipality pays the owner for its use, inspection is mandatory if the facility retains its vessel status.

Alternatively, such a facility may request designation as "substantially a land structure" (see section 10.1 of the Marine Safety Manual). h.

A vessel designated "substantially a land structure" is not considered a vessel for inspection purposes, however, it remains subject to the other regulations, such as those promulgated under the Ports and Waterways Safety Act.

It will also be subject to the building, electrical, and fire codes as may be applied by the local municipality.

Inspection and Certification of Floating Detention Facilities — IMPLEMENTATION.

a. Since the basic philosophy of Coast Guard and international regulations concerning protection and escape of passengers and crew is quite different from the concept of protecting and controlling prisoners and correction officials, guidance on the application of the vessel safety regulations for this unique service is provided by this Circular. b. Upon request from a state or local municipality, the Coast Guard will provide inspection and certification under the provisions of 46 C. F.R. Subchapter H for a floating detention facility that is, otherwise, not subject to inspection. Enclosure (1) to this Circular should be used as a guide in applying these regulations. c. Except as discussed in paragraphs 4.e and 4.f, floating detention facilities engaged in the carriage of "passengers for hire" are subject to and shall be inspected as passenger vessels. The guidance in enclosure (1) may also be applied to these vessels. d. The provisions of this Circular are to be applied not only to new construction, but also to existing vessels converted to detention facilities. For converted vessels, these provisions will be applied insofar as is reasonable and practicable. Further guidance may be sought from Commandant (G-MVI) where exceptions are noted. e. The provisions of this Circular apply to U.S. flag vessels. They also apply to foreign flag vessels in U.S. waters. A foreign flag floating detention facility, unless designated "substantially a land structure," must have a Coast Guard Certificate of Inspection (COI). The current international safety conventions do not address detention facilities, therefore, they cannot be considered to provide standards similar to those of the U.S. inspection standards. Inspection certificates issued by another administration will not be recognized. f. A floating detention facility which is permanently moored and thus taken out of navigation, will, upon request, be designated "substantially a land structure" and not be subject to the inspection laws of 46 U.S.C. NAVIGATION AND VESSEL INSPECTION CIRCULAR NO. 10-91 g. Except as otherwise specifically noted in enclosure (1), questions regarding the application of this Circular are to be directed to Commandant (G-MVI). End: (1) Inspection and Certification of Floating Detention Facilities

Sections it refers to

The plain-English explanation on this page was written with AI from the regulation text above and checked automatically before publishing: every quote appears in the text, every number comes from it, and a second model confirmed each statement adds nothing the text doesn't say. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.