How do you feel about plumb bows on cruisers?

[DMF Sailing]

Originally Posted by Training Wheels

That looks like it would be one of my worst nightmares at sea.

You mean this Southern Cross 35? Mind elaborating?

After all, she's "a ruggedly built, double-ended cutter intended for blue water passage-making with safety, comfort, and speed."

I realize intended for blue water passage-making are loaded words that invite controversy on this forum....

(Kira in my signature seems pretty transfixed by that sheer line...)

[rslifkin]

There's a Southern Cross 35 in my marina and I've gotta say, it does have a good look to it. In the water, it looks kinda like a PSC 34 / 37 with a pointier stern and a bit shorter overhangs (especially aft). But on land, it definitely looks more modern and a bit flatter underneath. There's a lot less bridge between the keel and skeg as well. No way it'll sail like a modern boat with a wide, flat stern, but I'd bet it's nothing like an old school full keel double ender either.

[Rohan]

I am curious, has anyone ever built a modern sailboat with the reverse of an overhang bow? I dont know if there's a term for it - but what if instead of upwards, the bow was slanted downwards so that the LWL was actually longer than the length on deck? I think maybe old Viking boats and Roman triremes were like this. You would definitely go through waves instead of over them, and dropping an anchor would be a challenge. Would that increase speed over a plumb bow? How would that affect stability?

[DMF Sailing]

Originally Posted by rslifkin

There's a Southern Cross 35 in my marina and I've gotta say, it does have a good look to it. In the water, it looks kinda like a PSC 34 / 37 with a pointier stern and a bit shorter overhangs (especially aft). But on land, it definitely looks more modern and a bit flatter underneath. There's a lot less bridge between the keel and skeg as well. No way it'll sail like a modern boat with a wide, flat stern, but I'd bet it's nothing like an old school full keel double ender either.

Someone on the forum has a Southern Cross 35 for sale. I'd give it a look if I could get up to Ontario.

Pacific Seacraft is what I thought of, too, just looking at it. Not that I've been out in one of those, either.

[DMF Sailing]

Originally Posted by Rohan

I am curious, has anyone ever built a modern sailboat with the reverse of an overhang bow? I dont know if there's a term for it - but what if instead of upwards, the bow was slanted downwards so that the LWL was actually longer than the length on deck? I think maybe old Viking boats and Roman triremes were like this. You would definitely go through waves instead of over them. Would that increase speed over a plumb bow? How would that affect stability?

Tumbledown hull design? This is not a sailboat, but stability has long been a subject of debate that the navy has sought to debunk.

Probably apples to oranges, but I wonder if this would hold true for a sailboat using this design: “You definitely have to get used to the roll, which is very short compared to other ships,” Carlson said. “For those of us who have been on cruisers, especially up top, you kind of lean over 15 degrees and you wonder if you are going to come back. We didn’t experience any of that. As long as you get used to the finer oscillation, it really handles very well."

[rslifkin]

Originally Posted by DMF Sailing

Someone on the forum has a Southern Cross 35 for sale. I'd give it a look if I could get up to Ontario.

Pacific Seacraft is what I thought of, too, just looking at it. Not that I've been out in one of those, either.

The only boat of that category I've sailed is a PSC 34. My impression is that like most narrower, rounder designs, it heels more than modern stuff. And it's not a fast boat in light air. The owner of that boat's attitude is that in less than 8 - 10 kts true, it's not worth the effort to put the sails up unless you'd be motorsailing for a good distance.

Once there's enough wind, however, it's pretty nice to sail, although it doesn't point like a race boat, nor does it tack like one. But it'll go upwind well enough for the most part. I personally find the pitching motion a little bit excessive, but it's better under sail than when motoring. Roll motion is fairly nice with the sails up, but with them down, it's every bit as fast a roll as my powerboat, just not quite as snappy at the ends of the roll (and it rolls further). It's definitely rolly downwind, although I don't know if that would improve with more speed (I haven't been aboard with a spinnaker up or tried wing and wing on it, so it's never been a fast ride downwind). The one I've sailed is rigged as a sloop with a 135 genoa on the furler rather than a cutter (although the owner just got the parts in to add the inner forestay and convert to a cutter rig).

[boatman61]

Personally I feel spray is more related to speed and/or sea conditions and nothing to do with the shape of the bow..
EG; my Wharram cats (21ft and 26ft) had long overhangs and when doing 11+ knots the twin bow waves would reach back to my helm position soaking me even in flat protected water..
Also plumb bow boats tend to have flat bottoms inducing slamming which contributes to the spray effect..
Laurent Giles tried countering bow spray by creating a knuckle for his Westerly designs running from the bow to around 6ft back to deflect the bow wave effect which was somewhat effective.

[belizesailor]

Originally Posted by Rohan

I am curious, has anyone ever built a modern sailboat with the reverse of an overhang bow? I dont know if there's a term for it - but what if instead of upwards, the bow was slanted downwards so that the LWL was actually longer than the length on deck? I think maybe old Viking boats and Roman triremes were like this. You would definitely go through waves instead of over them, and dropping an anchor would be a challenge. Would that increase speed over a plumb bow? How would that affect stability?

https://youtu.be/Ubb8-af_nnw

[boatman61]

Originally Posted by Rohan

I am curious, has anyone ever built a modern sailboat with the reverse of an overhang bow? I dont know if there's a term for it - but what if instead of upwards, the bow was slanted downwards so that the LWL was actually longer than the length on deck? I think maybe old Viking boats and Roman triremes were like this. You would definitely go through waves instead of over them, and dropping an anchor would be a challenge. Would that increase speed over a plumb bow? How would that affect stability?

We'll there was the much discussed Cat that came to grief during an owner assisted delivery on the US E coast a few years back..
Not really sure what exactly happened however my view was the bows dug in and a large following wave bent the rudders.
The Skipper is/was a celebrated delivery Skipper and guru to some I think.
It was a new design and this was No2.. have not heard anything about the build since so maybe it was discontinued.
Back in the early part of the last century and before, a few navies experimented with destroyers and battleships with the reverse bow however they died a death, never to be seen again.

[Dockhead]

Are we talking about plumb bows specifically, or boats with plumb bows plus wide flat aft sections?


That type of boat is great for day sailing and coastal cruising, when you don't get into too much weather. The form stability from the wide aft sections allows carrying a lot more sail, so they can be much faster. So I guess that would be my choice for that kind of use case.



But for my own boat and own cruising (which involves higher latitudes, being far offshore, and a lot of bad weather) I prefer moderate flare to the bow, which gives progressive buoyancy as the bow is immersed. This has the disadvantage of more pitching but the advantage of being much dryer. Also makes handling the anchor much much easier and less destructive.



Does a flared bow take away from waterline length? Depends on how you look at it. Take a boat of given LWL and add a flared bow to it, and it doesn't. Just adding a bit of GRP ahead of where the waterline ends.



So if you want BOTH dry AND fast just make the boat a little longer. There is a virtuous circle with longer boats -- take the same accomodation and make the boat longer, and you get better LWL, better D/L -- a more easily driven hull. Plus more seaworthy, better motion despite less D/L. That was always Dashew's idea. Struggling to make a smaller boat EITHER seaworthy and dry OR at least somewhat lively sailing, is something of a fool's errand. Those compromises get sharper and sharper, as the boat gets smaller.

[Montanan]

Originally Posted by Rohan

I am curious, has anyone ever built a modern sailboat with the reverse of an overhang bow? I dont know if there's a term for it - but what if instead of upwards, the bow was slanted downwards so that the LWL was actually longer than the length on deck? I think maybe old Viking boats and Roman triremes were like this. You would definitely go through waves instead of over them, and dropping an anchor would be a challenge. Would that increase speed over a plumb bow? How would that affect stability?

Yes, those are called reverse, or wave piercing bows.

[DMF Sailing]

Originally Posted by boatman61

Also plumb bow boats tend to have flat bottoms inducing slamming which contributes to the spray effect.. .

That had occurred to me...this Hanse has a flat bottom and a deep bulb keel...again, great for performance sailing with that high aspect rig

good for hooking lobster buoys, too, if that's how you get your jollies

[Clivevon]

Surprised no-one has mentioned Bristol Channel pilot cutters with their plumb bows:
https://cdnx.theyachtmarket.com/boat...8915085_wm.jpg
Sailed by 2 crew to take the pilot out to incoming ships - in all winds & weather & the fastest boat got their pilot the job. Real working boats.

[Clivevon]

More info here: https://en.wikipedia.org/wiki/Bristo...t%20two%20crew.

[boatman61]

Originally Posted by Clivevon

Surprised no-one has mentioned Bristol Channel pilot cutters with their plumb bows:
https://cdnx.theyachtmarket.com/boat...8915085_wm.jpg
Sailed by 2 crew to take the pilot out to incoming ships - in all winds & weather & the fastest boat got their pilot the job. Real working boats.

Its a US forum.. they don't know Brit boats..