Stepped hulls?

dubb · 11-04-2007, 11:02 AM

I understand the advantages of this design but what is the disadvantage of using a stepped hull? Why dont you see them on larger boats?

jeff56 · 11-04-2007, 01:49 PM

Intrepid uses them on larger boats,Dusky uses it on the 33 I believe,......I think fountain uses it,and so did the original rybo's....these are just my observations......I think I have seen them on some inboards also....

rocksandblues · 11-04-2007, 04:01 PM

the ventilation=speed advantage is not a factor in the larger boats.

Mirage36 · 11-04-2007, 04:08 PM

Advantages are realized on deep draft with narrow beam boats by aerating the surface contacting the water at high speed. Not practical for displacement hulls.

marlineer · 11-04-2007, 08:31 PM

Unless You are able to locate a thru-hull trannsducer fwd. of the step, it is very hard to fund a spot where You will get a good reading. In My opinion, the bennies far outweigh the negs. After My first summer with an Intrepid 280, I can say the ride, speed and economy (20gph @36kts. w/2 strokes!) are what stepped hulls are all about.

dubb · 11-05-2007, 12:01 PM

It seems like there is a large amount of surface tension on let's say 60' spencer. So why dont they use stepped hulls to ventilate such boats?

iguana1 · 11-05-2007, 12:04 PM

I believe the issue with larger boats is that the chine is usually underwater when running and I am not sure, but there could also be issues with cavitation in tunnel hulls.

11-04-2007, 11:02 AM	#1
dubb Hardcore fishacholic Join Date: Mar 2007 Posts: 83 Credits: 1,305.9	Stepped hulls? I understand the advantages of this design but what is the disadvantage of using a stepped hull? Why dont you see them on larger boats?

11-04-2007, 04:08 PM	#4
Mirage36 I use a green machine Join Date: Feb 2005 Location: IR Delaware Posts: 206 Credits: 1,221.5 Occupation: Self Employed	Advantages are realized on deep draft with narrow beam boats by aerating the surface contacting the water at high speed. Not practical for displacement hulls. __________________ Rob aka RM2 Owner of 36' Mirage Mate Dana Lynn Charters 46' Carman Custom Walkaround Member Indian River Captains Assoc

11-04-2007, 08:31 PM	#5
marlineer Sit down Shut up And fish Join Date: Aug 2006 Location: South Jersey Posts: 590 Credits: 1,705.3 Boat: Intrepid 289 Home Port: Stone Harbor, NJ Best Catch: Bonnie! Occupation: Yacht Sales Suck! So I am puttin' out fires.	1 Disadvantage Unless You are able to locate a thru-hull trannsducer fwd. of the step, it is very hard to fund a spot where You will get a good reading. In My opinion, the bennies far outweigh the negs. After My first summer with an Intrepid 280, I can say the ride, speed and economy (20gph @36kts. w/2 strokes!) are what stepped hulls are all about.

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11-04-2007, 01:49 PM	#2
jeff56 Cockpit Monkey In Training Join Date: Sep 2006 Posts: 36 Credits: 1,269.7	Intrepid uses them on larger boats,Dusky uses it on the 33 I believe,......I think fountain uses it,and so did the original rybo's....these are just my observations......I think I have seen them on some inboards also....

11-04-2007, 04:01 PM	#3
rocksandblues Anthony's Ark is a blowboater Join Date: Mar 2005 Location: Northern Neck, VA Posts: 345 Credits: 1,394.5 Boat: 35 Contender, 18' Winner cc Occupation: developer	the ventilation=speed advantage is not a factor in the larger boats.

11-05-2007, 12:01 PM	#6
dubb Hardcore fishacholic Join Date: Mar 2007 Posts: 83 Credits: 1,305.9	It seems like there is a large amount of surface tension on let's say 60' spencer. So why dont they use stepped hulls to ventilate such boats?

11-05-2007, 12:04 PM	#7
iguana1 Stop staring at my Avatar. Join Date: Oct 2006 Posts: 409 Credits: 1,786.3	I believe the issue with larger boats is that the chine is usually underwater when running and I am not sure, but there could also be issues with cavitation in tunnel hulls.