Insurance Glossary & Boating Terms


Width of a vessel at its widest point.


Lowest point of boat’s inner hull – goes the full length of the boat.

C/L length

Boat centerline length; a straight line from bow to stern directly through center of boat.


Where the bottom meets the inside of a boat. A soft chine is gently rounded. A hard chine is abruptly angled.


The amount you are responsible for paying in the event of a claim.

Disappearing Deductible

Deductible rates decrease by a percentage each year if insured has no claims. (Available in select markets)


A small sail, oar, or power boat. If carried or towed by a larger vessel, often called a tender.


The depth of the boat in the water.

Flash Arrestors

A device on the carburetor of an inboard motor designed to prevent backfires into the motor compartments.


The height of the deck above the waterline.


Rudder bracket on the hull of the transom.


(pronounced gunnel) The upper edge of a boat hull, usually where it meets the deck.


The amount stated by the manufacturer as peak-developed horsepower measured at the flywheel.


The body of a boat, exclusive of superstructure, between the deck and bottom of the keel.

Hull Value

In the case of a new purchase, your hull value is based on the total purchase amount.

Latent Defect

A flaw in the material or machinery which exists at the time of the building of the vessel and is not discoverable by the insured through ordinary methods of testing.

Lay up dates

Specified periods of time in which a policy requires a vessel to be unused (usually because of potential damage from cold weather exposure). All policy requirements differ depending on location of vessel and method of storage. Most layup periods can be found on the declaration page. Vessel is still insured during this period.

Personal Watercraft (PWC)

Vessels less than 13 feet in length upon which the owner sits or stands astride and is powered by an internal water jet propulsion.


(1) Keel extension protecting the rudder and propeller. (2) The fin projection at the bottom of the lower unit of an outboard motor or inboard/outdrive.

Total Loss Replacement

Coverage option which replaces insured boats in the event of a total loss with a new boat that is, to a possible extent, the same make and model and contains comparable equipment.


An explosion-proof system on inboard motor boats that evacuates fuel fumes from bilge and engine compartments.

Water line (boot top)

The horizontal plane through a hull at the water’s surface – normally when the vessel is at rest and fully loaded.

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