How fast is safe at night.

Discussion in 'All Things Boats & Boating' started by Frosty, Jul 18, 2012.

  1. Frosty

    Frosty Previous Member

    Even though my cat will cruise at 20kts I would never do that at night. I wondered what other power boaters felt a safe speed at night was.

    Looking at the pictures on Mannies new thread Danger at sea maybe not even moving at night might be sensible.
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  2. Silver Raven
    Joined: Oct 2011
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    Silver Raven Senior Member

    Gooday bloke. Nice or frightening question for sure. Just as a side not about your wording - - "cruise at 20kts" - "I wonder wht other power boaters felt a safe" - - noticed a 'point of interest a chap raised - - the 'chase boat' for the NZ - AC 72 - sail boat is a type of multihull with 1200 hp (2 x 300hp - o/b's) - so just how many hp does it take to catch a sailing boat ??? Ha ha

    Now Mr Baby-faced Pipe-smoking gentleman - the sailboat I'm purchasing in SE Asia - will easily cruise at 12 to 18kts - so we have a similar problem - - I've asked the question about how to protect - not only - what is my boat but also my life & 200 answers later - not one positive statement eccept from Rob Denny. I've built - 'collision resistant' bows on vessels for over 30 years but - thought some smart modern young person could tell me a better way. It seems that this is not the case. Seems there's lots of mouth but no substance - from some quarters - wonder where ???

    So - slow down at night - which is what we 'should all do' - - but Gawd - we all know that bit - as well - - I'm building a - false foam bow extension covered with several (or many) layers of kevlar/carbon/epoxy laminate @ enough of a slop that the bow that 'just might' ride up & over something that we hit & for sure we are going to hit something some day. Do remember that one of the best MOD 70's just this last week - hit a container - wiped out a c/b & limped across the Atlantic - so there is sure no guarantee - but then there never was. Caution & preperation is all that I can think of - Back to you bloke - any better ideas ?? Ciao, james
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  3. Frosty

    Frosty Previous Member

    Another plus for bulbous bows then!!
  4. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    You can't prepare or design for every eventuality and have a reasonable boat. That fact you're heading out of sight of land, suggests you're willing to take some level of risk. I'm suggesting this is part of the process. You can sail at what ever speed you like if you're crewed and equipped. If not, take the appropriate actions. A foam bow isn't going to be worth a damn if a whale decides to hump your fin, so do the best you can, stop worrying about things that only happen to a small fraction of a single percent, of the skippers out there and enjoy yourself.
  5. yipster
    Joined: Oct 2002
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    Location: netherlands

    yipster designer

    as mentioned, trowing out an anchor at night may be the wise action
    as we all know on open waters the moonlight is good enough to show a floating gas container under speed
    while on a moonless night even with a big spotlicht you dont see a thing and must power down to less than stepfoot speeds
    wich take you all night to get were you want, dangerous too!
    i know you dont like those modern mobil phones but they do give you all the weather reports, moonfases too
  6. SamSam
    Joined: Feb 2005
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    Location: Coastal Georgia

    SamSam Senior Member

    I wonder if a fish/depth finder with an audible alarm turned forward would spot stuff.
  7. Frosty

    Frosty Previous Member

    I think thats all a forward looking sounder is.
  8. Stumble
    Joined: Oct 2008
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    Location: New Orleans

    Stumble Senior Member

    I don't think there really is a definite answer. Conditions and traffic dictate to a large extent what a safe speed would be. Also things like radar and AIS can change the equation significantly.
  9. Alik
    Joined: Jul 2003
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    Location: Thailand

    Alik Senior Member

    In Gulf of Thailand, sometimes we see heavy wooden logs or tied thick bamboo sticks, also covered with shells. Not talking about fishing nets! Even driving daytime one needs to be careful; at night I would not drive over 8-12kts.
  10. Submarine Tom

    Submarine Tom Previous Member


    Great question, simple answer:

    What ever speed is safe under the circumstances, same as any other navigating situation.

    Just because it's daytime doesn't mean you can cruise at 20 knots, what if it's foggy or there is debris in the water like 20 foot logs, or there is heavy fishing traffic.

    Same with night time, maybe it's clear, calm and a full moon and there is no traffic or hazards for miles.

    The maximum speed under any condition is the one you can navigate safely at for your individual ability level and circumstances including vessel sea worthiness.

    There are simply too many variables to give a certain speed that is safe to travel at at night (or any time really) accept to say the speed at which you can safely navigate.
  11. Ike
    Joined: Apr 2006
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    Ike Senior Member

    How fast can you maneuver your boat is a better answer to this. Suppose you are traveling on a clear night, stars and moonlight. But you suddenly come upon an unlighted buoy? Can you you maneuver fast enough to avoid it? Th simple answer is slow down to a speed at which you can react fast enough to miss something that is within your range of visibility. In other words, how far you can see and how quickly you can react are the determinants of how fast you go. Anything that restricts your range of vision and your ability to react in time is a reason to slow down even more. Fog, overcast (no stars or moonlight) rain, volume of boat/ship traffic, weather, all affect you ability to see ahead and react quickly enough to avoid an accident. So the Key words are Slow down. My rule is if I think I am going too slow, then that's probably the right speed.
  12. masalai
    Joined: Oct 2007
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    masalai masalai

    I am in no hurry and day trip (anchor up most nights after 8 hours of travel mostly) and daytime cruise is 10 knots except when there is a nice obliging following swell, then I have been doing 19 knots and surfing in good light, & clear visibility...

    Voyages are planned to meet this objective and the only hop now planned is 480 miles Cairns to Samarai... These waters are usually clear of debris and I will defer departure waiting for a "weather window" for a 48 hour non-stop passage with the radar ON ALL NIGHT... and find out prior to leaving Cairns, what shipping to expect on that route... I will not travel solo for that leg...
  13. Frosty

    Frosty Previous Member

    It was not 'debris' that concerns me. It is the semi sunken containier and other such items as Mannie has posted on his thread danger at sea. Stuff like this will have you swimming in your underpants in seconds.

    A cored hull will be open like a blooming flower.

    The thought arose when someone recently asked me if I was delivering a power boat to Singapore would I slow down at night.

    The dilemma is that the customer wants his boat and does not want crew partying at anchor,-- against a possible impact which would rip the bottom out of it or very least the shafts and rudders immobilizing immediately risking sinking or at least a very expensive tow in.

    It makes shipping attractive.
  14. masalai
    Joined: Oct 2007
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    masalai masalai

    Debris for me includes anything that could damage my boat in any way that should not be there...

  15. Submarine Tom

    Submarine Tom Previous Member

    Unlit buoys are marked on charts. This would be poor seamanship and navigating to suddenly come across one unexpectedly, you'd be operating well beyond your safe ability as a seaman.

    Slow down.
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