Do you think that Fair Prin Seeker will start making slower boats

[henryf]

Sailing yachts are very narrow compared to motor boats and actually when we pass them in lumpy seas they seem to be doing a good impression of a see saw. The nose constantly gets buried in the water, spray comes up on deck the nose goes up again and so it continues. What they are good at dealing with is a beam sea because the sails and keel stop the thing rolling.

Surely a deep V hull allows the boat to ease it's way into the water when coming off a wave. A flat bottom would simply slam the water stopping instantly but the deep V initially cuts into the water then gradually opens up to add buoyancy and slow the downward movement.

I don't claim to be an expert in hull design so happily hold my hands up if I've got things all wrong.

From my personal perspective when I looked around prior to buying the present tub I couldn't see where displacement boats offered benefits. If we want economy we go slowly, if we want to go fast we can and if it looks like things are about to kick off in the water we hopefully don't go to sea. Speed means we aren't trying to predict the weather too far in the future and we can make best use of any weather / tidal windows.

Henry

 

[PowerYachtBlog]

At P speed, by definition you're not cutting the water at all.
Don't mistake the fact that you still need to dampen the impact with the waves (and the faster the speed, the higher such need - which lead to deep-V hull design), with the need to cut THROUGH the water.
Even with the P hulls which are best known for being able to take substantial waves without falling apart (like Magnum, Itama, etc.), the name of the game is still LIFTING, rather than cutting through.
The deep V is in fact meant to better absorb vertical, rather than horizontal impacts - though arguably all wave impacts in a boat are actually diagonal, but you see what I mean.

yes agreed when you go on a certain speed at 20 knots plus, but when a planning boat at - 19 knots if not less the bow works much more, and is taking the waves in horizontal way. I like to do this a lot in when I go around a head sea with waves at 2 meters plus, and the ride is more comfortable. Jim Wynn started this with the wide Magnum 38 (for a Mag of the time 38), and I think David Napier followed this thought to perfection with Bertram.
I rode a Baia 48 Flash not much big engines and anyways when it had the lenght of the waves it was unbeatable in head seas in my book see Horizontal effect, you go WOT in 2 meters+ height as long the boat had the length to catch the waves. 2 x480hp 15 tons weight 38 knots not even a slamming, Give her waves a bit longer to its length and due to its not very deep fore foot, think it was 32 degrees forward, and 20 degrees aft, the ride changes considerably.

A sailboat is very solid in most sea conditions if you sail, if you don't it is less comfortable or the same to a motor boat. Last year on my trip from Malta to Syracuse, in the middle of the road between Malta and Sicily we got some NE (ie Gregale) with 2 and sometimes even 3.5 meters, any ways I slowed down to about 14-15 knots still just planning tabs down, I saw three sailing boats (no sails) in the way and I can tell you I was seeing there keel as the head sea was riding into them. I am not sure that was not very much comfortable for anyone onboard.....
Many x-motor-boaters who buy a sail boat and do not sail do not understand that the mast is not there as a moment but its your most important tool, more so when there is a bit of sea

Yes I like to call the hydrodinamic effect as Opening Gently

 

[dj43]

Having recently spent over 500 quid on fuel going from Hamble to Weymouth and back it made me think about whether it is likely that the above named manufacturers will start to make slower more economical boats, this is not a moan about cost of fuel, I love my boat and happy to pay for the running costs, but I was just thinking that I wander how sustainable it is for the industry to keep selling vessels that burn so much jungle juice. I know there are many other manufacturers out there and a wide choice but will we ever see a slower heavier Princess for example..........

Having just completed a trip back from Weymouth in deteriating conditions,we were glad to have the benefit of being able to get back to cowes at planning speed , we did remark on route that if we had a displacement boat stabalisers were the way to go,we have been on our boat for three plus weeks so far cruising the west coast,and the number of motorboats out making passage we have seen would not get into double figures, so yes I would say the cost of feul is a factor in this,but as mentioned in previous posts,cutting your speed to displacement speed in a planning boat, conditions allowing, makes a vast improvement to feul burn, we have just refuelled and took on 750 ltrs with the log reading just under 200nm between legs, in an old 50+ footer was rather pleased .log reading 300nm+ and counting.

 

[MapisM]

Last year on my trip from Malta to Syracuse, in the middle of the road between Malta and Sicily we got some NE (ie Gregale) with 2 and sometimes even 3.5 meters, any ways I slowed down to about 14-15 knots still just planning tabs down, I saw three sailing boats (no sails) in the way and I can tell you I was seeing there keel as the head sea was riding into them. I am not sure that was not very much comfortable for anyone onboard.....

Well W, if you're convinced that there can be ANY sea condition on this planet where a P boat at 15kts is more comfy than a sailboat motoring at her hull speed (from a boat motion viewpoint, and with a comparable hull size of course), then I'm afraid we have no other choice than agree to disagree!

 

[IDAMAY]

A very interesting discussion. Having just completed 2300nm to Scandinavia and back in a SD boat I can sympathise entirely with the OP's original point! We spent over £8,000 in fuel but admittedly over a five month period.

Having owned both planing boats and now a SD boat, we do find the SD costs less in fuel than planing. I accept that this is mainly by going slower but the SD boat is without doubt better designed for doing things on the move. It has safer decks and the galley and other interior features are made more with function in mind than appearance.

In a head sea our experience is that the SD rarely slams even when being used in its planing form. OTOH it does roll in a beam sea and then we have to increase speed to make things more comfortable. This has a severe effect on fuel economy. So, I agree that stabilisation should be the way to go.

BUT there seem to me to be at least two obstacles to this at present:

1. For boats under 50 feet, which lets face it the majority of us still own or aspire to, it is difficult to find space for the extra equipment whether gyro, fin or other. Boat builders will need to build stabilisers into the original designs.

2. At present the additional costs of stabilisers (£40 - £60K if original equipment, more if retro fitted?) is disproportionate to the total cost of sub 50 foot boats.

What we need is small profile, low cost stabilisers that can easily be retro fitted. Any ideas folks?

Richard.

 

[rustybarge]

A very interesting discussion. Having just completed 2300nm to Scandinavia and back in a SD boat I can sympathise entirely with the OP's original point! We spent over £8,000 in fuel but admittedly over a five month period.

Having owned both planing boats and now a SD boat, we do find the SD costs less in fuel than planing. I accept that this is mainly by going slower but the SD boat is without doubt better designed for doing things on the move. It has safer decks and the galley and other interior features are made more with function in mind than appearance.

In a head sea our experience is that the SD rarely slams even when being used in its planing form. OTOH it does roll in a beam sea and then we have to increase speed to make things more comfortable. This has a severe effect on fuel economy. So, I agree that stabilisation should be the way to go.

BUT there seem to me to be at least two obstacles to this at present:

1. For boats under 50 feet, which lets face it the majority of us still own or aspire to, it is difficult to find space for the extra equipment whether gyro, fin or other. Boat builders will need to build stabilisers into the original designs.

2. At present the additional costs of stabilisers (£40 - £60K if original equipment, more if retro fitted?) is disproportionate to the total cost of sub 50 foot boats.

What we need is small profile, low cost stabilisers that can easily be retro fitted. Any ideas folks?

Richard.

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View attachment 35275

 

[MapisM]

Wow, 2300nm is indeed some serious cruising. And no piccies/report?

Also, may I ask you which is the boat you're talking about?
Just curious, because in the SD league there are some hulls which are almost as good at real trawlers at taking waves without slamming, but also some others which are nearer to "normal" P hulls, just with a different superstructure etc.

Re. stabs, I fully agree with all your thoughts.
Alas, I'm afraid it will always remain a pretty expensive equipment, also for small(ish) boats.
Trouble is, you need all the components which are necessary for bigger boats.
Yes, everything is smaller, but not much simpler.
That said, if you're interested in a retrofit, you might be interested to have a look at this thread:
http://www.ybw.com/forums/showthread.php?350520

 

[Nick_H]

Alas, I'm afraid it will always remain a pretty expensive equipment, also for small(ish) boats.
Trouble is, you need all the components which are necessary for bigger boats.
Yes, everything is smaller, but not much simpler

Why do you say that, if the volume was there there I think the price would eventually drop to a small fraction of the current price, and everything could be scaled down for smaller boats. There's little cost in the electronics (you can buy an inclinometer app for an ipad for £0.69), and software development is also cheap if the volume is higher. The fins could be moulded, so the only big issue is the DC motors but there will be huge spin off from automotive develoment in this area in the coming years. Assemble it all in a low cost country and fit it into the boat during build, and I can't see why a system for a small boat should cost more that £5k eventually

 

[MapisM]

Why do you say that, if the volume was there there I think the price would eventually drop to a small fraction of the current price

Yeah, but. The volume is not there, and I don't think it ever will.
After all, what you're saying should have already materialized in any other boat components (engines, electronics, s/steel fittings... you name it), while all prices still are well above any sort of comparable parts in real high volume markets, like truck engines, consumer electronics, etc.
Of course, this is also due to the fact that boaters are a lot of fat cows used to get milked, but the low numbers are also a true reason.
Anyway, I can predict anything but the future, and I sincerely wish to all of those who would like to have stabs on a small boat to be able to fit them with 5 grand quite soon.
Alas, I'm afraid I won't live long enough to see that happening...

 

[IDAMAY]

Slower Boats

Wow, 2300nm is indeed some serious cruising. And no piccies/report?

Also, may I ask you which is the boat you're talking about?
Just curious, because in the SD league there are some hulls which are almost as good at real trawlers at taking waves without slamming, but also some others which are nearer to "normal" P hulls, just with a different superstructure etc.

Re. stabs, I fully agree with all your thoughts.
Alas, I'm afraid it will always remain a pretty expensive equipment, also for small(ish) boats.
Trouble is, you need all the components which are necessary for bigger boats.
Yes, everything is smaller, but not much simpler.
That said, if you're interested in a retrofit, you might be interested to have a look at this thread:
http://www.ybw.com/forums/showthread.php?350520

Piccies/report - www.oceanstarblog.co.uk We have hundreds of photos but the thought of uploading them here over Chichester Marina's v slow WIFI is more than a little daunting!

Trader 42 - not sure if that is semi displacement or semi planing if either of these terms make any sense.

Just had lunch with a friend who has an Elling E4 who reckons that his single engine only burns about 2 litres per hour at 7kts if I remember the conversation correctly. They decided to accept the beam sea handling compromises this gives. This is essentially what we have done but with the option to get into the mid teens speed if conditions mandate it.

Thanks for the retrofit info.