Boating and marine service glossary

The boat's full length from the tip of the bow to the back of the stern. Slip fees, haul-outs and many hull cleaning quotes are priced per foot of LOA, but not all of them, so check which length a quote uses.

See also: Waterline length · Beam · Quote comparison worksheet

The length of the hull where it sits in the water. It is shorter than LOA. Some hull divers price by waterline because that is the surface they actually clean.

See also: LOA (length overall)

The boat's width at its widest point. Marinas use it to assign slips, and boatyards and haulers need it.

How deep the boat sits below the waterline at its deepest point (usually the keel or the lowest part of the drive). It decides which slips, channels and lifts the boat can use.

The underwater parts that drive and steer the boat: propeller, shaft, struts, cutless bearing and rudder. Hull cleaning quotes don't always include it.

See also: In-water hull cleaning · Zincs (sacrificial anodes)

A through-hull is a fitting that passes through the hull for water intakes or drains. A seacock is the valve that closes it. Both are inspected and exercised during a haul-out.

See also: Haul-out

The seal where the propeller shaft passes through the hull. Traditional packing is designed to drip slightly while the shaft turns.

The drive unit of an inboard/outboard (I/O) boat: the engine is inside the hull and the drive leg hangs off the transom. It has its own anodes and service schedule.

See also: Zincs (sacrificial anodes)

The hard, glossy outer layer on most fiberglass boats. Sun exposure oxidizes it, which is what compounding and waxing during a detail restore and protect.

Read more: Detailing

Varnished or oiled exterior wood (and sometimes polished metal) on a boat.

Standing rigging is the fixed wire or rod that holds a sailboat's mast up (shrouds and stays). Running rigging is the lines that raise and trim sails (halyards and sheets).

Read more: Rigging

A tank that stores sewage on board until it is pumped out. Federal rules call a holding tank a Type III marine sanitation device.^[1]

See also: Pump-out · No-discharge zone (NDZ)

Paint on the underwater hull that slows the growth of slime, weed and barnacles. Most release a biocide such as copper; non-biocide coatings rely on a slick surface and regular cleaning instead.^[2]

See also: Ablative paint · Hard paint · Copper leach rate · Non-biocide coating · Bottom paint

Antifouling paint that slowly wears away as the boat moves or is cleaned, exposing fresh biocide. It is soft, so divers clean it gently with soft tools; aggressive cleaning removes paint and releases more copper.

See also: Hard paint · In-water hull cleaning

Antifouling paint that forms a hard film and does not wear away. Biocide leaches out of the film over time, and old coats build up and eventually need sanding or stripping.

See also: Ablative paint

Silicone, ceramic or epoxy hull coatings with no biocide. California agencies recommend cleaning them every 2 to 4 weeks; manufacturers claim a useful life of 5 to 10 years.^[2]

How fast copper escapes from antifouling paint, in micrograms per square centimeter per day. California limits paints for recreational boats to 9.5 µg/cm²/day.^[3]

See also: TMDL (total maximum daily load)

Cleaning the underwater hull while the boat stays in the water, done by a diver. California guidance: wait at least 90 days after painting, then clean copper paint only when needed and no more than once every 30 days.^[2]

See also: BMP (best management practice) · In-Water Hull Cleaning Permit · Hull cleaning

A visible cloud of paint particles in the water during hull cleaning. It means the tool is too aggressive; several harbors prohibit it.^[4][5]

Blocks of zinc, aluminum or magnesium bolted to underwater metal. They corrode first, protecting the propeller, shaft and drive. Replace them at about half consumed.^[6]

Read more: Zincs and anodes

Galvanic corrosion happens when different metals sit in salt water together; anodes are the defense. Stray-current corrosion is caused by electrical current leaking into the water and can eat metal much faster.

See also: Zincs (sacrificial anodes) · Electric shock drowning (ESD)

Lifting the boat out of the water at a boatyard, usually with a travel lift, for bottom paint, running gear work, inspection or a survey.

Read more: Haul-out

A brief lift, often hanging in the slings for an hour or two, for a quick inspection or a small job, priced lower than a full haul with blocking.

A day the boat spends out of the water in the yard, often charged per foot per day.

A practice that limits pollution, such as using the softest tool that works when cleaning a hull. Some harbors require hull cleaners to be trained or certified in hull cleaning BMPs: Marina del Rey requires County certification, and Santa Barbara asks for training within the previous five years.^[7][8]

A Water Board limit on how much of a pollutant a water body can take, with a plan to cut loads to that level. Shelter Island Yacht Basin, Marina del Rey and Newport Bay have copper TMDLs, which is why hull cleaning is more regulated there.^[2]

Read more: Rule changes tracker

One of nine California Regional Water Quality Control Boards that set and enforce water quality rules, including copper TMDLs. Big changes also need State Water Board approval.^[9]

California Department of Pesticide Regulation. It regulates antifouling paints as pesticides and set the copper leach-rate cap. It does not license hull cleaners.^[3]

California State Parks' Division of Boating and Waterways. It runs the Boater Card program and boating safety and clean-boating programs.^[10]

Waters where sewage may not be discharged from vessels, treated or not. All California marine waters are a federal no-discharge zone for large passenger and large oceangoing vessels; that rule does not cover small recreational boats, but local rules may.^[11][12]

See also: Pump-out · Holding tank (Type III MSD)

Emptying a boat's holding tank at a station or by a mobile pump-out boat. Stations funded by Clean Vessel Act grants may charge no more than $5.^[1]

See also: Clean Vessel Act (CVA) · Pump-out

A federal grant program that pays for pump-out and dump stations. Funded stations must be open to the public with reasonable fees, capped at $5 per pump-out.^[1]

Proof of passing an approved boating safety exam. Since January 1, 2025 everyone who operates a motorized vessel on California waters needs one unless an exemption applies. It is valid for life.^[13][10]

Read more: Boater Card update

The registration number the California DMV issues to a vessel. It is displayed on both sides of the bow in plain block characters more than 3 inches tall, with the registration sticker nearby.^[14]

See also: USCG documentation · Mussel Fee Sticker

Federal registration of a vessel with the Coast Guard's National Vessel Documentation Center, as an alternative to state registration. A documented vessel doesn't need DMV registration but still owes California property and use tax.^[14][15][16]

A sticker required on California-registered recreational boats used in freshwater, including the Delta east of Chipps Island. Since October 22, 2026 it costs $21 if first bought in an even-numbered year or $42 in an odd-numbered year.^[17]

Read more: Mussel fee update

California tax owed on a boat bought without paying California sales tax to a dealer, such as a private-party or out-of-state purchase. DMV collects it at registration for undocumented boats; documented boats pay CDTFA directly.^[16]

Boats are taxable personal property. The county assessor where the boat is kept values it as of the January 1 lien date, and owners file an annual vessel property statement.^[18]

The Port of San Diego's bay-wide permit ($250) that every hull cleaning business needs to work in San Diego Bay. Marinas must check that divers hold it.^[19][5]

The City of Newport Beach permit required to provide a commercial service in Newport Harbor. The city's harbor fee schedule lists $424 initial and $95 renewal for service providers from July 1, 2026; the permit page itself still shows the 2025 fees ($398 / $386).^[20][21]

LA County's ID card for yacht and dock repair technicians, hull cleaners and other businesses working in Marina del Rey. Hull cleaners also need BMP certification.^[22][7]

A free CDTFA permit for businesses that sell taxable goods. A repairer is the retailer of parts, and needs to collect tax on them, when parts are more than 10% of the total charge or are billed separately.^[23]

Labor that makes a new item, such as new canvas. In California it is generally taxable, unlike separately stated repair labor.^[24]

A one-page summary of a business's insurance, usually on the ACORD 25 form, issued by its broker. It shows coverage but does not by itself give the marina any rights; that comes from an endorsement on the policy. Some harbors ask for the endorsement page to be attached.^[25]

See also: Additional insured · Certificate holder · COI request letter

Another party, such as a marina or harbor district, added to a policy by endorsement so the policy protects it too. Marinas usually specify the exact wording; Ventura Port District says a certificate without the endorsement attached is not in compliance.^[25][8]

See also: Certificate of insurance (COI)

The party a certificate of insurance is issued to, usually the marina. It is not the same as being an additional insured.

See also: Additional insured

Business liability insurance for injury and property damage to others. California's Department of Insurance lists watercraft and care, custody and control among its major exclusions, which matters for anyone who works on boats.^[26]

See also: Care, custody and control · Ship repairer's legal liability (SRLL)

Property that belongs to someone else but is in your hands, such as a customer's boat you're working on. Ordinary liability policies often exclude damage to it.^[26]

Marine insurance that covers damage to customers' vessels or equipment in the business's care during repair or installation work. Some boatyards require it of contractors.^[27]

Insurance for customer property in your care while ashore, such as cushions or canvas taken to a shop.^[27]

Marine liability insurance for the owner or operator of a vessel: injury to others and damage to others' property. Providers who run their own workboat, such as a pump-out boat, may need it; marinas ask owners for vessel liability too.^[27]

Federal workers' compensation for maritime workers. Since 2009, people employed to repair recreational vessels are excluded if they are covered by state workers' comp, but a boat that routinely carries passengers for hire or is in commercial service is not recreational for this purpose.^[28][29]

An endorsement in which the insurer gives up its right to recover a paid claim from another party, such as the marina. Ventura Port District asks for it on workers' comp.^[25]

Two ways a boat policy pays a total loss: agreed value pays the amount stated in the policy, actual cash value deducts depreciation.

American Boat & Yacht Council, which writes safety standards for boat building and repair and certifies individual technicians (electrical, engines, corrosion, refrigeration and more). Technician certification needs an exam plus two years' experience and lasts five years.^[30][31]

National Marine Electronics Association. It sets the NMEA 0183 and NMEA 2000 data standards for marine electronics and certifies installers.^[32]

Federal certification required for technicians who service equipment that could release refrigerant, including marine refrigeration and air conditioning.^[33]

California Professional Divers Association, the hull diver trade group that developed early in-water hull cleaning BMPs. We could not confirm a current course schedule.

A diver at the dive location who can help a diver in the water immediately. California's diving rules require one whenever an employee is scuba diving, along with line-tending or a buddy in the water. Recreational dive cards and harbor permits don't cover this.^[34][35]

Read more: Become a hull diver: diving safety rules

Coast Guard Operator of Uninspected Passenger Vessels credential, for carrying up to six passengers for hire. A credential is triggered by passengers for hire, meaning passengers who pay, directly or indirectly, to be carried.^[36]

See also: USL&H (Longshore and Harbor Workers' Compensation Act)

Devices that cut power when current leaks. An ELCI protects a boat's whole shore power system (ABYC E-11, 30 mA); GFCIs protect individual receptacles (5 mA). Test both monthly.^[37]

See also: Electric shock drowning (ESD)

Drowning caused by AC current leaking into the water near shore power, which paralyzes swimmers. Never swim near docks or boats on shore power. If someone may be getting shocked, don't go in after them: cut the power at the shore source, throw flotation and call 911.^[37][38][39]

Read more: Shore power safety guide

An inspection by a marine surveyor, most often before buying a boat (pre-purchase survey) or for insurance (condition and value survey). A pre-purchase survey often includes a haul-out and a sea trial; confirm what the quote covers.

Read more: Buying a boat in California

Taking the boat out under way to test engines and systems, typically during a survey or after engine work.

A work order is the written scope the technician works from. A not-to-exceed amount caps what can be billed without the owner's approval.

Read more: Service request brief