Design Questions - Bulbous Bow / Wake Smasher ?

Discussion in 'Boat Design' started by Edward Tafoya, Aug 24, 2018.

  1. Edward Tafoya
    Joined: Aug 2018
    Posts: 2
    Likes: 0, Points: 1
    Location: Las Vegas, Nv.

    Edward Tafoya New Member

    My 1'st thread start here !
    Are the Bulbous Bow addition's worth the work & money ? Do they really work ?
    My boat, 50' PowerCat, twin engine, 600HP.
    I understand the design improves, fuel economy, Smooth ride ? ?
    If it works, I'll do it !
    Is there a manufacturer out there, selling a good design ?
  2. jehardiman
    Joined: Aug 2004
    Posts: 3,686
    Likes: 1,072, Points: 113, Legacy Rep: 2040
    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    Welcome to the forum.

    Bulbs are not a "one-size fits all" or "just bolt one on" proposition. They are individually designed for the operational condition and hull form. Some hull forms and operational length to speed ratios will never benefit from a bulb. IF it is a displacement hull which spends 90% of its time at one specific speed in the proper Froude Number range AND one specific displacement AND cost of the design and installation is less than 1-2% of the total cost of fuel over the remaining life of the vessel, then there MIGHT be a economic benefit to installing bulbs (so think commercial fishing vessels, ferries, and other high operational hour vessels, not a once-a-month pleasure craft). Because of the design cost associated with the refit to avoid powering and balance issues retrofitting bulbs to any vessel, they are rarely fitted to non-commercial craft for economic reasons
    (ie fuel economy)
    and usually only by the manufacturer to fix other issues (such as poor pitch response or poor powering performance) so they don't have to scrap the hull moulds (cf the Aquila 44 power cat, but they did a lot of other mods to the hull lengthening it and modifying the stern). Bulbs also come with a host of other issues, such as fouling and damage.

    This is a topic that has been discussed before, so you can use the Search function in the upper right. Type in "bulbous bow" and you'll see threads on the topic show up.

    Bulbous Bow changes
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