Entering an anchorage, advice from Dad. "Don't make waves."

  • 26 Dec 2018 11:34 AM
    Message # 6972771

    "When entering a quiet anchorage, or even a small marina, slow down and back over your stern wake to disconnect it from your stern so you don't drag it along rocking all the boats. " Credit, Harry McGuane

    The rest of the story...

    Remember that stern wake you see at cruising speed?  It is connected hydraulically (in some way) to your stern.  Even if you slow your boat to absolute zero speed idle and continue forward, it will continue to follow your boat direction.  In the photos below you can see how long the waves continue behind you without diminishing. They move slow, but they will follow your boat.  So,  it seems like you are making zero wake entering the quiet anchorage.   But about 20 minutes after you enter, these wakes will enter following your course.  Have you ever been sitting in a nice quiet anchorage and suddenly get rocked by a good size wake and wonder who made that wake?!?!  There is a very good chance it was you. 

    I once saw a great aerial photo of Admiralty Inlet with a boat motoring along on a calm day and the photo clearly showed the stern wake effect (Transient wake, between the V shaped wave pattern) very apparent for several miles behind the boat, long after the bow (V shaped) waves had reached each shore over a mile to each side of the boats course. The photos attached below, were all I could find to show the phenomena. Yet, you can see, unless something disrupts the stern wake... it doesn't seem to diminish at all.  if you are ever on an airplane on a calm day, look at the boat wakes to see how far they extend. 

    I see these wakes being carried into anchorages happen all the time, but for me it is a hobby to watch it happen.  I fully realized the scope one day when I was in the tender with my son and he stopped at the bay entrance and I realized he was following his granddad's advice, as he stopped, backed up a few feet and continued at idle into anchorage.  We watched our friend's tender, which only slowed to idle, drag a wake into bay, and watched every boat rock, as our friends tender went in ahead of us. Even though they were going just at idle and appeared to be making zero wake, a nearly invisible roller rocked every boat. 

    However, there is a solution my Dad was taught and passed on to us.  If you come to a full stop, and then back up just a dozen feet,  your stern wake will stop right there and never enter the anchorage.  It hydraulically disconnects from the mass of your boat. I am sorry, I don't know how the hydraulic science works, but try it some times and watch it.  And then watch other boats.  This happens with all boats making a wake, a large cruiser, a sailboat motoring at 6 knots, and a humble tender.  

    Regards

    Kittiwake


    Image result for boat wake aerial


    Image result for boat wake aerial

    Related image

    Last modified: 26 Dec 2018 11:36 AM | Anonymous member

Corinthian Yacht Club of Seattle
7755 Seaview Ave NW 
Seattle WA 98117
(206) 789-1919 

office@cycseattle.org 



CYC Gold Partner


Thank you to CYC Platinum Partner


CYC Gold Partner


And CYC Business Member

pre-2018 Web Archive
pre-2011 Web Archive

47° 41.14' N 122° 24.22' W



CYC Silver Partner



And CYC Business Member


Powered by Wild Apricot Membership Software