| my account | login-logout | resources | classroom help | support | catalog | home | get webcard |

Online Classroom


Post New Topic  New Poll  Post A Reply
search | help desk | commons
  next oldest topic   next newest topic
» Online Classroom   » Emergency Navigation   » Public Discussion of Emergency Navigation   » Estimating set and drift

   
Author Topic: Estimating set and drift
David Burch


 - posted March 14, 2007 08:55 PM      Profile for David Burch           Edit/Delete Post 
In figure 13-13 of Emergency Navigation, there is a trick procedure for figuring how much you will get set in a current depending on the ratio (current speed)/(boat speed) and on the angle of the current on the bow: broad on the bow, on the beam, or on the quarter.

The formulas are simple and easy to use... and very useful underway, even when not in an emergency.

the caption of that figure states in part:

"With current on the bow, boat speed is retarded by roughly three quarters of the current speed, which is about what you gain with current on the quarter."

In redoing the second edition, this sentence stood out. I am assuming this means that our SMG with current on the bow will be reduced to SMG = S-0.75*C and that current on the quarter the SMG = S + 0.75*C.

The exercise is work out a few numerical cases to see if this is true.

From: Starpath, Seattle, WA


All times are Pacific  
Post New Topic  New Poll  Post A Reply Close Topic    Move Topic    Delete Topic next oldest topic   next newest topic
Hop To:

Starpath School of Navigation

Copyright, 2003-2018, Starpath Corporation

Powered by Infopop Corporation
UBB.classicTM 6.3.1.1