The types of keels

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The types of keels: Advantages, disadvantages and utilities for the boat

The keel of a boat plays an essential role in its stability, its maneuverability, and its performance at sea. There are several types of keels, each of which has its own characteristics that are suitable for different styles of navigation. This article aims to give a clear vision of each type of keel, both for novices and experienced sailors, highlighting the advantages, disadvantages, as well as the models of boats that are equipped with them.

  • 1. Long keel

    The long keel extends over a large part of the length of the hull, providing excellent directional stability.
    • Advantages: Very stable, especially in rough sea conditions. It also promotes gentle navigation on the high seas.
    • Disadvantages: Makes the boat slower to maneuver, especially in tight spaces. It can be penalizing in terms of speed in weak winds.
    • Utility: Ideal for long-distance cruise ships where stability takes precedence over performance.
    • Models: Westerly Centaur, Nicholson 32, Rustler 36, Cape Dory 30, Tradewind 35.

  • 2. Fin keel (Fin keel)

    This short and deep keel, often used on modern boats, allows good maneuverability.
    • Advantages: Very efficient in regatta and in light wind conditions. It improves the responsiveness of the boat to the controls.
    • Disadvantages: Less stable in rough sea conditions, with an increased risk of grounding in shallow waters.
    • Utility: Ideal for regatta boats and fast cruisers, where performance and speed are essential.
    • Models: Beneteau First 40, J/109, X-Yachts 35, Dufour 36, Jeanneau Sun Odyssey 349.

  • 3. Swivel keel (Swing keel)

    This keel can be raised or lowered to adjust the boat's draft.
    • Advantages: Allows access to shallow waters and facilitates trailer transport. Useful for coastal navigation.
    • Disadvantages: Less stable on the high seas, requires regular maintenance of the pivot mechanism.
    • Utility: Perfect for coastal cruises and small transportable boats.
    • Models: MacGregor 26, Southerly 42, Hunter 270, Jeanneau Sun 2000, Parker 27.

  • 4. Weighted keel (Bulb keel)

    A keel with a bulb at its base to lower the center of gravity without increasing the depth of the draft.
    • Advantages: Improves stability without requiring a deep draft. Very effective in regatta boats.
    • Cons: May slightly affect handling under certain conditions.
    • Utility: Ideal for high-performance boats requiring good stability and speed.
    • Models: Bavaria 42, Hanse 315, Beneteau Oceanis 38, Dehler 34, Elan 333.

  • 5. Two-blade keel (Bilge keel)

    Two keels are placed on either side of the hull. This type of keel is mainly used in tidal areas.
    • Advantages: The boat can land at low tide without excessive lodging. Very practical in coastal areas with high tidal amplitude.
    • Disadvantages: Less efficient upwind (headwind) and in terms of pure speed.
    • Utility: Ideal for coastal navigation and shallow anchorages.
    • Models: Westerly Centaur, Moody 31, Hunter Horizon 26, Saber 27, Leisure 23.

  • 6. Double rudder keel (Twin keel)

    Two small keels are placed on the sides of the hull, often associated with dinghies and light boats.
    • Advantages: Better stability at sea and in shallow waters. Allows you to keep the boat upright when it is stranded.
    • Disadvantages: Less efficient in open sea conditions, especially upwind.
    • Utility: Small coastal cruisers and dinghies.
    • Models: Jeanneau Tonic 23, Parker 275, Sadler 25, Ufo 365, Hunter 19.

  • 7. Duck keel (Lifting keel)

    A retractable keel that allows you to adjust the draft without compromising performance.
    • Advantages: Flexibility for deep and shallow waters, without affecting navigation performance too much.
    • Disadvantages: Mechanical complexity, requires more maintenance.
    • Utility: Cruise ships and race-cruises.
    • Models: RM 890, Pogo 30, Southerly 32, Feeling 32, UFO 435.

  • 8. Divertable keel (Centerboard keel)

    A small fixed keel combined with a removable fin to adjust the depth of the boat.
    • Advantages: Ideal for navigating in areas with varied depths.
    • Disadvantages: Less efficient on the high seas, limited stability in difficult conditions.
    • Utility: Coastal cruises, perfect for shallow areas.
    • Models: Jeanneau Tonic 23, Comet 23, Etap 21i, Etap 26i, Beneteau First 21.

  • 9. Fin keel with ballast (Winged keel)

    A weighted keel with wings to lower the center of gravity without increasing the draft too much.
    • Advantages: Allows to have a good compromise between stability and reduced draft.
    • Disadvantages: Less efficient during tight maneuvers.
    • Utility: High-performance cruise and regatta boats.
    • Models: Beneteau First 35, Dehler 38, Elan 37, Jeanneau Sun Fast 37, Bavaria Cruiser 37.

  • 10. Short fixed keel

    A small rigid keel, often used on small coastal cruisers.
    • Advantages: Allows you to navigate in shallow areas without sacrificing too much stability.
    • Disadvantages: Less stable on the high seas, limited performance.
    • Utility: Quiet coastal cruises.
    • Models: Catalina 25, Hunter 25, Etap 24i, Com-Pac 23, Precision 23.

  • 11. Semi-long keel

    Between the long keel and the fin keel, it offers a balanced combination of stability and performance.
    • Advantages: Good stability and correct performance at open sea.
    • Disadvantages: Less efficient than a fin keel for speed, but more stable than a short keel.
    • Utility: Mixed offshore cruises.
    • Models: Hallberg-Rassy 29, Contessa 32, Vancouver 28, Albin Vega, Rival 34.

  • 12. Tandem keel

    Two keels arranged one behind the other to improve performance and stability.
    • Advantages: Better stability than a single keel, and optimizes speed with less draft.
    • Disadvantages: Complex design, not very common.
    • Utility: Regattas and performance cruises.
    • Models: RM 1260, Jeanneau Sun Fast 3200, Akilaria RC2, Class 40, Mini Transat.

  • 13. Integral dinghy

    This type of boat has a retractable keel allowing it to sail in very shallow waters.
    • Advantages: Great flexibility, can access almost all coastal areas.
    • Disadvantages: Less stable on the high seas, limited performance in difficult conditions.
    • Utility: Coastal cruises and light exploration boats.
    • Models: UFO 435, Allures 39.9, Boreal 44, Garcia Exploration 45, Feeling 44.

What to check when buying a used boat?

  • The shell: Check the general condition, look for signs of osmosis (bubbles under the gelcoat), cracks or impact zones.
  • Keel and structure: Look for cracks at the junction between the keel and the hull. Incorrect alignment can signal poorly made repairs or impacts.
  • Rigging: Examine the mast cables and the fastenings. Any corrosion may indicate safety problems.
  • Engine: Test it in operation, check the oil level, the condition of the filters, and the operating time of the engine.
  • Electronic systems: Make sure that all equipment is working properly (GPS, depth sounder, VHF, etc.).
  • Tightness and Humidity: Look for signs of water infiltration, especially around portholes, seals and holds.

The purchase of a boat is an important investment, and it is crucial to carry out a thorough inspection before finalizing the purchase.