NAICS 488390 Quarterly Industry Report
Other Support Activities for Water Transportation
Comprehensive industry research for valuation professionals, business owners, buyers, and lenders
NAICS Code: 488390Sector: 48Updated: Q1 2026
About This Report
This NAICS 488390 industry profile draws from Census Bureau[5] establishment and revenue data, Bureau of Labor Statistics[6] employment statistics for water transportation support activities, and SBA[7] size standard thresholds. Fair Market Value updates this report quarterly, monitoring environmental regulation changes that affect vessel cleaning practices and ballast water management requirements. Our research team provides NAICS 488390 valuation professionals with current benchmarks on marine service contract rates and fleet maintenance demand cycles.
Industry Snapshot
Key metrics for the other support activities for water transportation industry.
Industry Definition & Overview
Other Support Activities for Water Transportation (NAICS 488390) encompasses establishments primarily engaged in providing services to water transportation not classified elsewhere, including vessel cleaning, ship scaling, floating dry dock operations, marine surveying, and other ancillary maritime services. This residual category captures specialized maritime support functions that fall outside port operations, cargo handling, and navigational services.
Firms in this industry serve both commercial shipping fleets and recreational vessel operators. Marine surveyors inspect hull conditions, cargo damage, and compliance with classification society standards. Ship cleaning companies remove marine growth, apply anti-fouling coatings, and decontaminate cargo holds between voyages. Floating dry dock operators provide vessel haul-out and underwater repair services at locations without permanent drydock infrastructure. Revenue in this sector correlates directly with vessel traffic volumes and fleet maintenance cycles.
Census Bureau data[5] shows this industry includes both small specialized firms and larger marine service companies offering bundled support packages. Bureau of Labor Statistics[6] occupational data indicates workers range from marine surveyors holding professional certifications to industrial cleaners and painters performing hull maintenance. Geographic concentration follows major port complexes and shipyard clusters along the Gulf Coast, Pacific Coast, and Atlantic seaboard. Environmental regulations, including ballast water discharge standards and anti-fouling paint restrictions, continue to drive demand for specialized cleaning and treatment services that keep vessel operators in compliance with federal and state maritime law.
What's Included in This Industry
- Marine surveying and vessel inspection services for classification compliance
- Ship hull cleaning, pressure washing, and marine growth removal
- Floating dry dock operations for vessel haul-out and underwater repairs
- Ship scaling and surface preparation for coating application
- Cargo hold cleaning and decontamination between voyages
- Marine fuel bunkering coordination and fueling services
- Vessel provisioning and chandlery supply services
- Bilge and ballast water management and treatment services
- Marine environmental response and oil spill cleanup services
- Underwater hull inspection and diving services for commercial vessels
NAICS Classification Hierarchy
| Level | Description | Code |
|---|---|---|
| Subsector | Support Activities for Transportation | 488 |
| Industry Group | Support Activities for Water Transportation | 4883 |
| NAICS Industry | Other Support Activities for Water Transportation | 48839 |
| National Industry | Other Support Activities for Water Transportation | 488390 |
Related NAICS Codes
| Code | Description | Relationship |
|---|---|---|
| 488310 | Port and Harbor Operations | Port and harbor operators that manage terminal facilities where marine service companies perform vessel cleaning, surveying, and maintenance work alongside berths |
| 488320 | Marine Cargo Handling | Marine cargo handling firms that coordinate with ship cleaning companies to prepare cargo holds between loading cycles at port terminals |
| 488330 | Navigational Services to Shipping | Navigational service providers including tugboat operators and salvage firms that perform distinct vessel assistance functions separate from maintenance services |
| 336611 | Ship Building and Repairing | Ship building and repairing establishments that perform major vessel overhauls in permanent drydocks, while floating dry dock operators handle smaller repairs afloat |
| 561720 | Janitorial Services | Janitorial service establishments that perform general cleaning work but are excluded from specialized ship cleaning and decontamination services classified here |
| 562910 | Remediation Services | Environmental remediation services that perform oil spill response and marine pollution cleanup work overlapping with maritime environmental response operations |
Geographic Concentration
Top states by share of national establishments.
| # | State | % Est. | Total Est. |
|---|---|---|---|
| 1 | Florida | 27.2% | 200 |
| 2 | Texas | 11.8% | 87 |
| 3 | Louisiana | 11.7% | 86 |
| 4 | California | 7.6% | 56 |
| 5 | New Jersey | 4.8% | 35 |
| 6 | Washington | 3.7% | 27 |
| 7 | New York | 3.0% | 22 |
| 8 | Alaska | 2.5% | 18 |
| 9 | Alabama | 2.5% | 18 |
| 10 | Virginia | 2.5% | 18 |
% Of Establishments
0%
27%
Source: County Business Patterns, U.S. Census Bureau[3]
SBA Lending Summary
88
Total SBA Loans
$44.4M
Total Loan Volume
$505K
Average Loan Size
11 yrs
Average Loan Term
9.57%
Average Interest Rate
488
Jobs Supported
Source: SBA 7(a) Program Data, U.S. Small Business Administration — FY 2025[4]
Key Insight: Under SBA size standards[7], NAICS 488390 businesses qualify as small with average annual receipts up to $47 million. Marine service firms can access SBA 7(a) loans[8] for equipment purchases, vessel acquisition, and working capital. The 504 loan program[9] supports purchase of floating dry docks, marine cleaning equipment, and waterfront property for service operations. Small marine service companies often face seasonal revenue fluctuations tied to shipping cycles, making SBA working capital facilities especially useful.
Top SBA Lenders
| # | Lender | Loans | Volume | Avg Loan |
|---|---|---|---|---|
| 1 | Northwest Bank | 16 | $22.0M | $1.4M |
| 2 | JPMorgan Chase Bank, National Association | 8 | $4.6M | $580K |
| 3 | Northeast Bank | 8 | $4.0M | $500K |
| 3 | Citizens Bank | 8 | $4.0M | $500K |
| 5 | Midwest Regional Bank | 8 | $3.8M | $478K |
Frequently Asked Questions
Common questions about this industry.
What types of businesses are classified under NAICS 488390?
Marine surveying firms, ship cleaning companies, floating dry dock operators, vessel provisioning services, bilge water treatment providers, and marine environmental response companies are classified under NAICS 488390. This code captures water transportation support activities not covered by port operations (488310), cargo handling (488320), or navigational services (488330) per Census Bureau classification[10].
How is NAICS 488390 structured within the transportation sector?
NAICS 488390 is the residual code within Industry Group 4883 (Support Activities for Water Transportation). It captures specialized maritime services excluded from the three primary water support codes: port operations, cargo handling, and navigational services. Ship janitorial work falls under 561720, and major vessel repairs belong in 336611.
What is the SBA size standard for NAICS 488390?
The SBA size standard[7] for NAICS 488390 is $47 million in average annual receipts. This threshold uses the five-year average of gross receipts to determine small business eligibility for federal contracting preferences and SBA lending programs.
What NAICS codes are most closely related to 488390?
Closely related codes include 488310 (Port and Harbor Operations), 488320 (Marine Cargo Handling), 488330 (Navigational Services to Shipping), 336611 (Ship Building and Repairing), and 562910 (Environmental Remediation Services). These codes cover different aspects of the maritime service chain from vessel operations to environmental cleanup.
What industries have the strongest business relationships with NAICS 488390?
Deep sea freight carriers (483111) and coastal shipping lines (483113) are primary customers for hull cleaning, surveying, and hold decontamination. Shipyards (336611) refer lighter maintenance work to marine service firms. Bureau of Labor Statistics[6] data covers combined employment for all water transportation support activities including these specialized services.
What activities are included in NAICS 488390?
Included activities cover marine surveying, hull cleaning, floating dry dock operations, ship scaling, cargo hold decontamination, vessel provisioning, ballast water management, and marine environmental response. Major ship overhauls in permanent drydocks are excluded per Census Bureau[10] guidelines and classified under NAICS 336611.
Are NAICS 488390 businesses eligible for SBA loans?
Yes, marine service firms below the $47 million threshold can access SBA 7(a) loans[8] for equipment and working capital, and 504 loans[9] for floating dry docks, marine equipment, and waterfront property. Seasonal revenue patterns tied to shipping cycles make SBA credit lines particularly valuable.
Where are NAICS 488390 businesses geographically concentrated?
Marine service firms cluster near major port complexes and shipyard centers. Gulf Coast locations (Houston, New Orleans, Mobile) have high concentrations due to offshore energy vessel support. Pacific Coast ports (Los Angeles/Long Beach, Seattle) and Atlantic gateways (Hampton Roads, Jacksonville) also support large marine service sectors per Census Bureau[5] establishment data.
Sources & References
Government datasets and editorial sources used in this report.
- [1]U.S. Bureau of Labor Statistics, Quarterly Census of Employment and Wages bls.gov
- [2]U.S. Census Bureau, Economic Census census.gov
- [3]U.S. Census Bureau, County Business Patterns census.gov
- [4]U.S. Small Business Administration, SBA 7(a) Loan Program Data data.sba.gov
- [5]Census Bureau data data.census.gov
- [6]Bureau of Labor Statistics bls.gov
- [7]SBA sba.gov
- [8]SBA 7(a) loans sba.gov
- [9]504 loan program sba.gov
- [10]Census Bureau classification census.gov
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