Is Semi-Displacement Hull better than Deep V Hull ?

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Saw a Trader 50 has a semi displacement hull. Then I remember read an old thread about an old member who sold his Fairline Squadron 59 Drumbeat to buy a Trader just because he wants the semi-displacement hull. That makes me ask: is the Semi Displacement hull better than the Deep V hull? Thanks.

Edit: Let's say for cruising at sea and coastal area cruising.
 
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penfold said:
That; semi-d generally offers a softer ride in extreme conditions at a cost of more rolling, less hull volume and greater drag, deep vee gives the opposite. This is a generalisation though.
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What about a Semi-D with a Seakeeper?

Although very expensive would that would counter the roll issue?

?
 
Having owned eight planing boats and two semi displacements and enjoyed them all, I reflect that I now prefer semi displacement, particularly when fitted with stabilisers. They also have the benefit of lower fuel costs compared with planing boats at their designed cruising speed.

Having said that, I came across semi displacement late in my boating life when life was generally more sedate. I did enjoy haring around in sports cruisers in my boating youth.
 
For leisure boats, I found almost all the popular brands are using Deep V, such as Princess, Fairline, Sunseeker, Sealine, Jeanneau, etc. But only a few brands are using semi displacements, such as Trader and Grand Banks. Why?
 
Lucas Gan said:
For leisure boats, I found almost all the popular brands are using Deep V, such as Princess, Fairline, Sunseeker, Sealine, Jeanneau, etc. But only a few brands are using semi displacements, such as Trader and Grand Banks. Why?
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There are dozens of motorcycle manufacturers making sports bikes, but only Harley Davidson making Harley Davidsons...Not better, not worse, just appealing to a smaller target audience who prefer slow & steady.
 
Lucas Gan said:
For leisure boats, I found almost all the popular brands are using Deep V, such as Princess, Fairline, Sunseeker, Sealine, Jeanneau, etc. But only a few brands are using semi displacements, such as Trader and Grand Banks. Why?
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Yeah it does seem to limit the market but i guess it better to focus on what your good at instead of being a jack of all trades. Someone told me that Semi-D is the best of both worlds

I do think that more boat manufacturers will start doing Semi-D boats because of the advancement of engines and technology etc

Sunseeker are currently building the Semi-D Ocean range of superyachts

Absolute yachts are probably the only company that does a Deep-V & Semi-D version of all their boats

Absolute Yachts, the Italian company specializing in building luxury yachts.

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westernman said:
Because it is not sexy if you can only do 14 knots.
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I don't know about not sexy but if a 42 trader needs say 800hp to cruise at 14knts a 42 ft deep vee will be doing 25knts, admittedly not in the same conditions but with more speed you will be safely tucked up in a berth while the Semi-d is still out there slugging it out.
 
Chris_d said:
I don't know about not sexy but if a 42 trader needs say 800hp to cruise at 14knts a 42 ft deep vee will be doing 25knts, admittedly not in the same conditions but with more speed you will be safely tucked up in a berth while the Semi-d is still out there slugging it out.
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Confirms exactly what I said. A lot of people need to be able to do 25 knots.
 
westernman said:
Confirms exactly what I said. A lot of people need to be able to do 25 knots.
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When i was assessing what sort of boat i wanted i did it (wrongly or rightly) by how long i wanted to spend on a boat.

Planing Hull = 1-2 days
Semi-Displacement = Week +
Displacement = Month +

As i wanted to spend longer than a weekend on my boat but still wanted a bit of performance and comfort then i opted for a Semi-Displacement

I wouldve bought an Absolute ❤ by now but they use IPS engines and where i will be using my boat can have a lot of large logs and debris after hurricane season so its a bit of a risk.

The lovely people on this board warned me of the dangers and i took it into account.

So im still undecided. I'll probably get a V-Hull Flybridge (Shafts Drive/V-Drive) for a few years while i gain experience and then get a Semi-D later on

(y)
 
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Lucas Gan said:
Saw a Trader 50 has a semi displacement hull. Then I remember read an old thread about an old member who sold his Fairline Squadron 59 Drumbeat to buy a Trader just because he wants the semi-displacement hull. That makes me ask: is the Semi Displacement hull better than the Deep V hull? Thanks.

Edit: Let's say for cruising at sea and coastal area cruising.
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Its like asking "what's better, a Rolls Royce or a Porsche?".

It depends entirely what you plan on using the boat for.

Just bear in mind that travelling long distances by motor cruiser isn't a particularly enjoyable experience and that's why most people probably have a cruising that's no more than 100 miles of their home base.
 
petem said:
Its like asking "what's better, a Rolls Royce or a Porsche?".

It depends entirely what you plan on using the boat for.

Just bear in mind that travelling long distances by motor cruiser isn't a particularly enjoyable experience and that's why most people probably have a cruising that's no more than 100 miles of their home base.
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Agree .
Just a point of order a “ deep V “ in those that know is over 20 degrees dead rise .
Lets not confuse Sunseekers , Priny s , FL s fly bridges .They are planing but not deep V or semi D .
They are medium V s .

Adding from experience , we have spent 3 weeks + stints on a planing boat both a normal medium v sports boat Sunseeker and my current deep V .
Stability running is gained by speed , no rolly polly wet ride .Speed = dryness as the splash is outrun it lands on the rear aspect not in the middle where pax are sat comfortable .

Local weather + climatic conditions are worth investigating where you wanna boat .
Eg in the AM in the Med there is often a calm window of a 2/3 hrs before the wind gets up .But to do 100 miles in 3 hrs is a a nice imho option .

As far as semi D and planing , it’s down to Hp .You need a lot of Hp to cruise in the 30-40 knot range .
This costs in terms of boat space and buying the things in + ancillaries like tanks + strainers+ shafts , props to match them .

Out running weather is a nice option as well .Unless you have done it’s hard to explain but essentially opens up more passage planning options .
We were once anchored up Porquerolles way ( Bouba stamping ground when his boats actually in the water :D )
Nice dsy etc but mistral started to blow up from the W .No issues as we were under a lee cliff .
6 pm geny on evening meal prepping etc etc .All eaten and packed up by 7-30 pm ( Mid June ) waves in the bay getting bigger huge white horses washing down E .
Our boat starting to swing on anchor with the inevitable buffeting and yachties arriving anchoring a bit close as “ room at the inn “ was running out .
Oh 8ugger it we are off .
Up anchor and 8 pm set off albeit down wind to do 60 + miles back to Cannes .
Wind and waves such you dissapeared in the troughs and went up steep crests etc .
30 knots and surfed it back for 10 pm just in time to turn the nav lights on .The weather increasing to F8 behind us .
Far better to be port bound next day with a hire car and a Hollie blowing out @ sea , than stuck swinging about praying a yachie is not gonna drag into you or a midnight arrival does not smack into you shiny polished gel coat .

You just could not do that in a 14 knot D semi planer without the large risk of a broach , .The mountainous sea running faster and a crest picking up the round stern and turning it .
 
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Portofino said:
Agree .
Just a point of order a “ deep V “ in those that know is over 20 degrees dead rise .
Lets not confuse Sunseekers , Priny s , FL s fly bridges .They are planing but not deep V or semi D .
They are medium V s .

Adding from experience , we have spent 3 weeks + stints on a planing boat both a normal medium v sports boat Sunseeker and my current deep V .
Stability running is gained by speed , no rolly polly wet ride .Speed = dryness as the splash is outrun it lands on the rear aspect not in the middle where pax are sat comfortable .

Local weather + climatic conditions are worth investigating where you wanna boat .
Eg in the AM in the Med there is often a calm window of a 2/3 hrs before the wind gets up .But to do 100 miles in 3 hrs is a a nice imho option .

As far as semi D and planing , it’s down to Hp .You need a lot of Hp to cruise in the 30-40 knot range .
This costs in terms of boat space and buying the things in + ancillaries like tanks + strainers+ shafts , props to match them .

Out running weather is a nice option as well .Unless you have done it’s hard to explain but essentially opens up more passage planning options .
We were once anchored up Porquerolles way ( Bouba stamping ground when his boats actually in the water :D )
Nice dsy etc but mistral started to blow up from the W .No issues as we were under a lee cliff .
6 pm geny on evening meal prepping etc etc .All eaten and packed up by 7-30 pm ( Mid June ) waves in the bay getting bigger huge white horses washing down E .
Our boat starting to swing on anchor with the inevitable buffeting and yachties arriving anchoring a bit close as “ room at the inn “ was running out .
Oh 8ugger it we are off .
Up anchor and 8 pm set off albeit down wind to do 60 + miles back to Cannes .
Wind and waves such you dissapeared in the troughs and went up steep crests etc .
30 knots and surfed it back for 10 pm just in time to turn the nav lights back .The weather increasing to F8 behind us .
Far better to be port bound next day with a hire car and a Hollie blowing out @ sea , than stuck swinging about praying a yachie is not gonna drag into you or a midnight arrival does not smack into you shiny polished gel coat .

You just could not do that in a 14 knot D semi planer without the large risk of a broach , .The mountainous sea running faster and a crest picking up the round stern and turning it .
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I have a diesel leak that I’m busy trying to trace......hopefully it will be an early season start for me???
 
ShaneAtSea said:
Yeah it does seem to limit the market but i guess it better to focus on what your good at instead of being a jack of all trades. Someone told me that Semi-D is the best of both worlds

I do think that more boat manufacturers will start doing Semi-D boats because of the advancement of engines and technology etc

Sunseeker are currently building the Semi-D Ocean range of superyachts

Absolute yachts are probably the only company that does a Deep-V & Semi-D version of all their boats

Absolute Yachts, the Italian company specializing in building luxury yachts.

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Er Nope no deep V ^^^^ .
More like low V not even medium.
Theres no info i could find in the two trials of the 58 .Every other number except dead rise .
But the big marketing BS alarm is the IPS ….it’s gotta be flat at the back , the mounting pads for the pods .
Otherwise if you were to rip out my motors in my 23 degree deadrise and install VP IPS on that degree of V the thrust vectors when turning would roll the boat ….badly .Marina manoeuvres , parking it would tip everything off a table and open lockers etc .
You know the ECU / joystick decides just to swing one pod and give it revs , say the wind blows etc .

Sticking pods on deep V or more accurately a medium v ( below 20*degrees ) facing straight Fwds works .
But once you start the fancy parking malarky the steep inclined plane of un toward thrust vectors takes over .

Aside the gear boxes would lean inwards and nut each other in the ER in any other than a pretty shallow dead rise.Low V .

Floating apartments is a more accurate term .NOT deep V that’s a hilariously term .
 
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