Powerboating Course Flashcards

Displacement Boats

• Displacement boats have hulls designed to move through water at slow to moderate speeds.
• Characterized by good maneuverability, directional stability, load capacity, and performance not significantly impacted by load.
• Their speed is limited by hull length, experiencing excessive rolling when waves hit sideways.

Hull Speed

• Hull speed is the maximum speed of a displacement boat when waves trap the hull between the bow and stern.

Planing Boats

• Planing boats transition from displacement to semi-displacement, then to planing, achieving higher speeds.

Characteristics of Planing Boats

• These boats consume more fuel past planing speed due to increased friction and are uncomfortable in rough conditions.

Types of Planing Boats

• Include flat bottom hulls, Vee bottom hulls, cathedral hulls, soft-inflatable hulls, and Rigid-Inflatable Boats (RIBs).

Flat Bottom Hulls

• Flat bottom hulls are inexpensive to build, have good load capacity, but struggle to maintain course at low speeds and provide a rough ride in waves.

Vee Bottom Hulls

• Vee bottom hulls excel in maintaining direction at speed; deeper V shapes perform better in choppy waters but may roll at rest.

Cathedral Hulls

• Cathedral hulls feature multiple forward V shapes transitioning to flat aft sections, offering good low-speed tracking and rolling resistance but are uncomfortable in rough seas.

Soft-Inflatable Hulls

• Soft-inflatable hulls are lightweight and portable, with high buoyancy but low directional stability, leading to a rough and wet ride.

Characteristics of Rigid-Inflatable Boats (RIBs)

• RIBs combine stability and buoyancy of inflatables with performance of Vee hulls, excelling in rough waters.

Multihulls

• Multihulls have multiple hulls (e.g., catamarans) and exhibit good speed stability, rolling resistance, and shallow drafts.

Personal Watercraft (PWC)

• PWCs operate using a water jet drive, allowing various riding positions. They provide good agility, speed, and maneuverability.

Propulsion Systems

• Powerboat drive units typically consist of an engine and a propulsion type - propeller or water jet.

Propeller Functionality

• The propeller generates thrust; its direction of rotation determines forward or reverse motion. Prop size is determined by diameter and pitch.

Cavitation

• Cavitation occurs when low pressure on propeller blades creates vapor bubbles, disrupting flow and reducing thrust.

Water Jet System

• Water jets operate without a propeller; water is drawn in, pressurized, and expelled to move the boat.

Trim and Tilt Control

• Adjusting the drive angle improves boat performance.

Engine Controls

• Includes dual function controls (combine throttle and gearshift), single function controls, throttles, and joystick controls.

Boat Dimensions

• Key dimensions include length overall, beam (width), draft (depth), freeboard (height above water), and waterline length.

Outboard Motors

• There are two main types: two-stroke and four-stroke motors, differentiated by lubrication methods and power strokes.

Outboard Engine Components

• Important components include choke, primer pumps, tilt lock-release level, throttle and gearshift controls, and safety features.

Fueling Procedures

• Distinct procedures for two-stroke and four-stroke engines include mixing oil with gasoline and ensuring proper venting and securing of fuel tanks.

Inboard Engines

• Inboard engines function similarly to automotive engines, adapted for marine environments.

Diesel vs. Gasoline Inboard Engines

• Diesel engines offer reliability and torque for larger boats, while gasoline engines are lighter, catering to high-performance applications.

Inspection and Starting Procedures

• Thorough inspections ensure safe operation, covering oil levels, fuel lines, leaks, and proper engine starting sequences.

Cooling Systems

• Most inboard engines use seawater for cooling; regular checks on the exhaust flow are crucial to prevent overheating.

Drive Types

• Various types of drives exist in marine technology, including stern drives, fixed propeller shaft drives, and jet drives.### Stern Drives
• Also known as inboard/outboard (I/O), combine features of inboard engines and outboard motors.
• Engine is mounted inside the boat, with a power train passing through the transom to a stern drive mimicking the lower part of an outboard motor.
• Stern drives can be tilted upward when not in use and are turned for steering.

Stern Drive Inspection

• Check hydraulic fluid for power trim control; typically found in a reservoir mounted inside the transom.
• Inspect propeller blades and neoprene sleeve for integrity.

Shaft Drives with Fixed Propellers

• Propeller shaft extends from the gearbox transmission through a sealed stern tube in the hull.
• A rudder is necessary for steering since the propeller does not swivel.

Propeller Shaft Through-Hull Seal

• Sealing mechanisms vary; common types include PTFE (Teflon) "dripless" seals and packing boxes using flax rings.
• Packing boxes intentionally allow a small amount of water leakage for lubrication as shafts rotate.

Jet Drives

• Utilize a large water pump impeller to accelerate water flow for propulsion, powered by gasoline or diesel engines.
• Offer excellent steering capabilities at all speeds, except when slowing down.
• Mid-to-large jet drives use deflectors for steering and reverse, while PWC and sport boats may utilize swiveling nozzles.

Jet Drive Inspection

• Ensure smooth operation of the jet drive control.
• Verify hydraulic oil level and inspect jet drive impeller condition through access cover (ensure engine is off and transmission is neutral).
• Confirm that the jet drive rotates freely.

Pod Drives

• Enhance maneuverability, especially in close-quarter situations.
• Improve performance and fuel efficiency.
• Usually installed as twin pods on powerboats over 30 feet in length and controlled with a joystick.

Pod Drive System Components

• Consists of a propeller drive unit with contra-rotating propellers, either rear-facing or forward-facing.
• Includes a transmission control unit located inside the hull and an engine, which can be diesel or gasoline.

Life Jacket Requirements

• Must be appropriately sized and fit properly to avoid riding up in water.
• Favorably bright colors (like yellow or orange) are preferred for visibility.

Captain's Responsibilities

• Monitor local weather conditions, tides, and potential hazards while boating.
• Maintain a lookout for other vessels and adhere to navigation rules to prevent collisions.
• Ensure safety management and compliance with legal measures while operating.

Navigation and Float Plans

• A navigation plan details the intended trip with navigational aids and compass headings.
• A float plan left onshore includes route details, planned times, and emergency contacts.

Boarding Procedures

• Ensure the boat is securely tied to the dock and board from the closest side.
• Maintain balance while boarding to keep the boat level.

Operator Responsibilities

• Adhere to maximum capacity limits and ensure passenger safety.
• Monitor fuel levels and stay aware of weather updates through channels like VHF radio.

Capacities Plate/Label

• Required on all powerboats under 20 feet built after October 31, 1972, clearly displaying capacity limits.
• Absence of a label necessitates calculating capacity based on the boat's dimensions.

Types of Lines and Their Uses

• Nylon: Strong, elastic; ideal for anchor and dock lines.
• Polyester/Dacron: Less stretchy, gentle on hands; multipurpose use.
• Polypropylene: Floats, difficult to knot; suitable for waterskiing towlines.

Knot Types and Uses

• Cleat hitch: Attaches a line to a cleat securely.
• Bowline: Creates a non-slipping loop at line end.
• Round turn with two half hitches: Secures fender lines.

Docking Techniques

• Use a bowline fastened to the bow and run forward, alongside stern and spring lines for effective securing.
• Adapt looping techniques to accommodate other boats' lines.

Coiling Techniques

• Twisted line should be coiled clockwise in rounded loops to prevent kinking.
• Braided line coiling direction is flexible; figure-8 loops prevent tangles.

Heaving a Line

• Secure one end to the boat, throw underhand aiming next to the person, not directly at them.

Securing Boats to Docks

• Employ either bow-stern configuration or double-stern and bow lines to firmly secure the boat.

Weather Report Sources

• Obtain updates via the Internet, TV, or NOAA marine weather from VHF radio.

Engine and Transmission Shift Practice

• Shifting gears should occur at idle RPM to avoid engine or transmission damage.

Stopping Techniques

• Coasting stop: Gradually reduce throttle, shift to neutral while allowing distance to stop.
• Quick stop: Involves immediate throttle reduction, a brief pause in neutral, and shifting to reverse to halt movement.

Steering with Tiller and Wheel

• Tiller: Turn opposite to desired direction for effective maneuvering.
• Wheel: Turn in the same direction as intended travel.