Displacement - SailNet Community
LinkBack Thread Tools
post #1 of 4 Old 12-17-2002 Thread Starter
Junior Member
Join Date: Sep 2001
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0

How is a boat''s displacement computed? If a boat has a gross tonnage of 24,000 lbs, is its displacement the same, or is there an equation to derive a different figure?
LeLai201 is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
post #2 of 4 Old 12-17-2002
Senior Member
Join Date: Dec 2001
Posts: 360
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 14

The displacement has to at least equal the overall weight of the boat - or it will sink.

~ Happy sails to you ~ _/) ~
928frenzy is offline  
Quote Quick Reply Share with Facebook
post #3 of 4 Old 12-17-2002
Senior Member
pirateofcapeann's Avatar
Join Date: Aug 2002
Location: Gloucester, Mass. USA
Posts: 373
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 14

When a boat is floating, it displaces an amount of water which weights exactly equal to the weight of the boat. Hence the term: Displacement.

As far as Gross Tonnage, that figure would reference the displacement of the vessel AND the weight of the cargo the vessel can carry. That figure is used in documenting a vessel.

For more information on that aspect, check out: www.uscg.mil/hq/g-m/vdoc/nvdc.htm
pirateofcapeann is offline  
Quote Quick Reply Share with Facebook
post #4 of 4 Old 12-17-2002
Senior Member
paulk's Avatar
Join Date: Jun 2000
Location: CT/ Long Island Sound
Posts: 2,611
Thanks: 4
Thanked 26 Times in 25 Posts
Rep Power: 16

It must be theoretically possible to calculate the displacement of a boat - naval architects do it all the time. The result can be numbers that are quite different from what the boat actually ends up weighing. Maybe the NA forgot to include a figure for full tanks. Maybe he left off 500 feet of chain. On bigger boats, stuff like this may make a difference of a half inch in the floating lines - no big deal. On smaller boats it can make a bigger difference, and they may go back and revise the printed numbers they publicize after they actually get a sample one to weigh.
paulk is offline  
Quote Quick Reply Share with Facebook

Quick Reply

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Forum Replies Last Post
boat check - to Jeff H and others maiden Boat Review and Purchase Forum 21 12-05-2006 02:55 AM
perfect cruiser for under $250k? pdshipl Boat Review and Purchase Forum 4 04-01-2004 04:15 AM
Displacement vs Length TADIAS General Discussion (sailing related) 5 12-16-2003 06:54 AM
Input from Cruisers please. Speedy50 Cruising & Liveaboard Forum 13 10-16-2003 01:12 PM
Purchasing through Charter Programs jillskor Boat Review and Purchase Forum 13 09-09-2001 07:30 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome