Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 06-09-2017, 11:26   #1
Registered User

Join Date: Apr 2007
Location: New England
Boat: lagoon 380 s2
Posts: 615
Side to Side motion on a powerboat

I am just wondering as a sailboat owner with a wife who gets seasick what the motion on a powerboat is.

I would think that a trawler would have roughly motion, it going the same speed (6-10 kts).

I am wondering about the 30 to 40' cabin cruisers/fishing boats/searays, etc. that go 20+ kts.

In 2-4' chop or swells both abeam and on, does it not affect the boat as it is on a plane? Sorry to be a newbie on this, I have actually never been on one of these boats. Thanks.
__________________

jbinbi is offline   Reply With Quote
Old 06-09-2017, 11:28   #2
Registered User
 
hobopacket's Avatar

Join Date: Nov 2016
Posts: 374
Re: Side to Side motion on a powerboat

Up at speed on plane, very little rocking motion as you would get going slow.

Trade off? Of course! With a little seas you can get a beating from pounding waves at speed.
__________________

hobopacket is offline   Reply With Quote
Old 06-09-2017, 11:53   #3
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29° 49.16’ N 82° 25.82’ W
Boat: Pearson 422
Posts: 13,448
Re: Side to Side motion on a powerboat

As Hobopacket said, a powerboat at speed on a plane or semi-planing for a larger boats, the motion is almost all pitching (the bow bouncing up and down) and very little yaw and roll (twisting/turning and side to side rolling). The yaw and roll are generally considered the most uncomfortable and most likely to cause sea sickness.

If the seas are rough the boat could pitch a lot and even bang as it comes down from a wave top (called pounding) and you could have to slow down then the yaw and roll are back.

How much a 2-4' chop on the beam would effect the boat would depend on the boat. The difference from 30-40' can be significant. Also would depend on the hull design; deep v, shallow v, beam of the boat and how steep and choppy the waves. I ride on a friends 33' power boat and at 20-35 kts 2' chop is like nothing. 4' it will pound a little going into the waves and a little roll if the seas are beam on.
__________________
The water is always bluer on the other side of the ocean.

Sometimes it's necessary to state the obvious for the benefit of the oblivious.

Rust is the poor man's Loctite.
skipmac is offline   Reply With Quote
Old 06-09-2017, 12:03   #4
Registered User

Join Date: Apr 2007
Location: New England
Boat: lagoon 380 s2
Posts: 615
Re: Side to Side motion on a powerboat

Appreciate the input. At 20 to 35 kts on a 33' boat, I am assuming you are using 10-20 gph?
jbinbi is offline   Reply With Quote
Old 06-09-2017, 12:05   #5
Registered User

Join Date: Apr 2017
Posts: 41
Re: Side to Side motion on a powerboat

In the 40'+ trawler range, you can have active or passive stabilization, or both. Both options can be very effective. Also, some smaller boats are even adding in a gyro stabilizer. They are even being placed on larger center console fishing boats.
spearfish3 is offline   Reply With Quote
Old 06-09-2017, 12:08   #6
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29° 49.16’ N 82° 25.82’ W
Boat: Pearson 422
Posts: 13,448
Re: Side to Side motion on a powerboat

Quote:
Originally Posted by jbinbi View Post
Appreciate the input. At 20 to 35 kts on a 33' boat, I am assuming you are using 10-20 gph?
Boat is a 33' Grady White with twin 300 hp outboards. I think it burns a lot less than that but have to ask.

Boat is heavy, solid deep v and a very comfortable ride.
__________________
The water is always bluer on the other side of the ocean.

Sometimes it's necessary to state the obvious for the benefit of the oblivious.

Rust is the poor man's Loctite.
skipmac is offline   Reply With Quote
Old 06-09-2017, 12:54   #7
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 20,655
Re: Side to Side motion on a powerboat

At planing speed no rocking/rolling, but the problem is the banging. It's bone jarring if you try to go thru heavy chop. So you end up slowing down and rolling anyway. The only answer I have to your problem is: catamaran or tri.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is online now   Reply With Quote
Old 06-09-2017, 12:57   #8
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 20,655
Re: Side to Side motion on a powerboat

Quote:
Originally Posted by jbinbi View Post
Appreciate the input. At 20 to 35 kts on a 33' boat, I am assuming you are using 10-20 gph?
Yeah, on say 26-29 ft with two 250 HP outboards cruising at say 3.5k-4k rpm/35 knots speed you are going to burn 14+ gph. But you are going to get 35 miles too.
In a trawler at 8 knots you are burning 1.5-2gph So maybe 8 gallons for the 35 miles trip... more or less.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is online now   Reply With Quote
Old 06-09-2017, 13:02   #9
Registered User

Join Date: Jan 2015
Location: Cebu
Boat: Cranchi Atlantique 48
Posts: 277
Re: Side to Side motion on a powerboat

As others have said, it will depend on the boat and the waves what a certain speed feels like. But the great thing is, at any given situation, you can just pull the throttle a little bit back or forth in order to find the most comfortable speed :-)
Zven is offline   Reply With Quote
Old 06-09-2017, 13:08   #10
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29° 49.16’ N 82° 25.82’ W
Boat: Pearson 422
Posts: 13,448
Re: Side to Side motion on a powerboat

Quote:
Originally Posted by Cheechako View Post
Yeah, on say 26-29 ft with two 250 HP outboards cruising at say 3.5k-4k rpm/35 knots speed you are going to burn 14+ gph. But you are going to get 35 miles too.
In a trawler at 8 knots you are burning 1.5-2gph So maybe 8 gallons for the 35 miles trip... more or less.
Just heard back from my son-in-law with the 33 Grady. With twin 300 hp 4 strokes he's burning 28 gph at 30 mph. Burns about 25% less at 25 mph.

The Grady White is a very heavy boat. Burns more than I thought. Would burn a little less in a lighter boat but probably wouldn't handle the seas like the Grady.

Went with him to gas up on Monday. He was down about half. Cost $650.00 to top off the tanks.
__________________
The water is always bluer on the other side of the ocean.

Sometimes it's necessary to state the obvious for the benefit of the oblivious.

Rust is the poor man's Loctite.
skipmac is offline   Reply With Quote
Old 06-09-2017, 14:07   #11
Registered User
 
Kenomac's Avatar

Join Date: Jan 2012
Location: Somewhere in Nova Scotia heading to Italy
Boat: Oyster 62 Cutter, Oyster 53 Cutter (for sale)
Posts: 9,553
Re: Side to Side motion on a powerboat

Have your wife take some Bonine over the counter sicksick medication.
Kenomac is offline   Reply With Quote
Old 06-09-2017, 14:38   #12
Registered User
 
Simi 60's Avatar

Join Date: Jun 2016
Location: Australia
Boat: Milkraft 60 ex trawler
Posts: 1,146
Re: Side to Side motion on a powerboat

We simply wait for calm days before doing long passages.
If doing shorter trips in rougher weather we tack.
Head up or down not doing the optimal course, but doing the comfortable one, then tack across when the angles are right until reaching the destination.

Bigger boat but it is our home and we do use glassware so try and keep her on the level.
Simi 60 is offline   Reply With Quote
Old 06-09-2017, 16:02   #13
Senior Cruiser
 
DeepFrz's Avatar

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Winnipeg
Boat: None at this time
Posts: 8,099
Re: Side to Side motion on a powerboat

There are a number of videos on youtube that show trawlers in heavy seas. You can see the difference with and without stabilizers. Makes a huge difference in comfort and ability to ward off sea sickness.
DeepFrz is offline   Reply With Quote
Old 06-09-2017, 17:33   #14
Registered User
 
Simi 60's Avatar

Join Date: Jun 2016
Location: Australia
Boat: Milkraft 60 ex trawler
Posts: 1,146
Re: Side to Side motion on a powerboat

Quote:
Originally Posted by DeepFrz View Post
There are a number of videos on youtube that show trawlers in heavy seas. You can see the difference with and without stabilizers. Makes a huge difference in comfort and ability to ward off sea sickness.
Huge difference in cost and maintenance for actives as well, especially if in a remote location.
Simi 60 is offline   Reply With Quote
Old 07-09-2017, 10:09   #15
Registered User

Join Date: Jun 2014
Posts: 87
Re: Side to Side motion on a powerboat

Buzzards Bay 33 displacement cat


2006 Buzzards Bay 33 Power Boat For Sale - www.yachtworld.com
__________________

daysgoneby is offline   Reply With Quote
Reply

Tags
boat

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not 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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
What is it Called When a Boat Leans Side to Side? chucklet321 Monohull Sailboats 36 01-11-2012 20:23
Dual helms side by side Bluewaters2812 Propellers & Drive Systems 24 28-10-2012 05:10
For Sale: Jewelry Store and Home Side by Side ChesapeakeGem Classifieds Archive 0 07-09-2012 13:52
Trans SCOP Side Effects: Dizziness, Post Motion Sickness rpoint16 Health, Safety & Related Gear 3 06-09-2011 17:50
Never mind the sunken powerboat on the right side of the picture marty9876 Off Topic Forum 2 14-07-2008 11:53



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 14:18.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.