Physics of heaving to

[Nightsky]

Originally Posted by JPA Cate

I'll confess, from the first picture, I thought we were dealing with a motor yacht, not a motor-sailer. She looks like she doesn't heel much. One of the deals about heaving to is that the boat will heel to the wind, and since the force goes up with the square of the velocity, even if she sits on an even keel when hove to at 20 knots, she is likely to heel at 50. If she is able to keep her head up to the weather, and you might need the storm jib to help with that-- the ride should be okay. But tiring, noisy (which adds to the fatigue). I wouldn't volunteer to go out and test it.

Ann

Ann I believe your first assumption is motor yacht is correct. I will go on the same assumption regarding Delfin and answer thus. In my previous working life as an albacore tuna fisherman on the westcoast of NA, in a 93' steel boat, aft wheelhouse very similar in style to the Delfin, we "hove to" almost every night except those instances when we ran all night to new fishing grounds. Very common to put the boat in neutral, shut the engine down and drift, regardless of the weather. Up to a point! Up to about 40 knots or so, it could be done in relative safety, if uncomfortable. Beyond 40 knots wave crests break and become dangerous, so we would just jog in to the waves. One thing you learn is that all boats have different drift characteristics. Generally, they tend to lay abeam to the seas (not a great attribute) and the speed at which they drift varies widely between different hull shapes. If I wanted to drift more slowly, i would turn my rudder hard over as if to keep the bow up wind. If I had sea room (no boats down wind of me), I would center the rudder for a nicer ride but would be many miles away by morning from where I last fished. These were the drift characteristics of my boat, YMMV. On top of that, some boats tend to drift bow first, that is, make some way, while others tend to drift stern first. After a while we would know whose boat did what, and we could set up drift room after shutdown, so that our boats would drift apart rather than come together. Very useful to know the characteristics of your boat and those around you.

[Delfin]

Originally Posted by Nightsky

Ann I believe your first assumption is motor yacht is correct. I will go on the same assumption regarding Delfin and answer thus. In my previous working life as an albacore tuna fisherman on the westcoast of NA, in a 93' steel boat, aft wheelhouse very similar in style to the Delfin, we "hove to" almost every night except those instances when we ran all night to new fishing grounds. Very common to put the boat in neutral, shut the engine down and drift, regardless of the weather. Up to a point! Up to about 40 knots or so, it could be done in relative safety, if uncomfortable. Beyond 40 knots wave crests break and become dangerous, so we would just jog in to the waves. One thing you learn is that all boats have different drift characteristics. Generally, they tend to lay abeam to the seas (not a great attribute) and the speed at which they drift varies widely between different hull shapes. If I wanted to drift more slowly, i would turn my rudder hard over as if to keep the bow up wind. If I had sea room (no boats down wind of me), I would center the rudder for a nicer ride but would be many miles away by morning from where I last fished. These were the drift characteristics of my boat, YMMV. On top of that, some boats tend to drift bow first, that is, make some way, while others tend to drift stern first. After a while we would know whose boat did what, and we could set up drift room after shutdown, so that our boats would drift apart rather than come together. Very useful to know the characteristics of your boat and those around you.

Yes she is a motor yacht, I suppose. I restored her masts because was that how she was originally built in 1965. Great info, Nightsky - exactly what I was looking for.

[Eben]

Originally Posted by Delfin

I think that's correct regarding balance. The forces certainly increase, and exponentially, but uniformly on all areas of windage.

Regarding Pardey's advice, as I recall, his objective is to avoid any forereaching in order to generate the turbulent slick to windward that kills breaking waves. That is the point of his bridle arrangement on a para anchor. What I find interesting with this vessel is that she naturally moves slowly 90 degrees downwind in the winds I've experienced. I guess the concern would be that in stronger winds, as Ann suggests, the increased boisterous nature of the waves might push her off that alignment with the result that you did start getting hit by breaking waves. Wind doesn't scare me. Waves do.

As the current owner of the boat the book was written on, and now having experienced the conditions you were asking about I can add this to the conversation.

When we were in 50 knots with 5 meter seas and 2 meter breakers on top of them, being scared was actually not an issue (I'm not tough by a long shot and was worried I might be terrified in those conditions). We had a bit of an issue with Taleisin Tacking on her own while hove to in the bigger stuff and the bridle is meant to stop that. We finally got the hang of it (we were hove to 3 times on our first off shore passage). The bridle must be lead mid ships to be effective. You have to adjust it so that it hold the boat pretty much 50 degrees to the waves. This helps to avoid the boat tacking on it's own and getting the para anchor rode stuck under the bobstay and chafe through (it doesn't take long so check on it often), if you do a bit of searching for my blog (the admins made it clear that I'm not welcome to post a link to it here) you can find pictures of this.

Another thing to add is that the harder it blew the more stable and comfortable it was. This to me would suggest that there's an optimum point where heaving to is more comfortable than sailing. At one point we opted to slow Taleisin down rather than heave to as it was more comfortable to do so and conditions weren't dangerous, we just needed to kill time till the winds and currents shifted so we could make way towards our destination.

I hope that helps a bit.

[Paul L]

Is Taleisin still engineless?

[Eben]

Originally Posted by Paul L

Is Taleisin still engineless?

Yes and No. It depends on how you look at it. She doesn't have an inboard engine and is unlikely to get one while we're owning her. She does how ever have an outboard motor which started out as a 20 HP motor and is now down to a 6HP motor. We take it off when we go offshore so she's effectively engineless while crossing oceans. We only use the engine to get in an out of harbours marinas and mooring fields if it's a tight fit or illegal to do so. The motor is mounted in such a way so that there's not a single hole in the boat because of it.

We have been using this configuration for about 5000 miles now and it seems to be practical without taking away too much from the way she sails. We don't like using the motor and use is sparingly.

Does that answer your question?

[Paul L]

Originally Posted by Eben

Yes and No. It depends on how you look at it. She doesn't have an inboard engine and is unlikely to get one while we're owning her. She does how ever have an outboard motor which started out as a 20 HP motor and is now down to a 6HP motor. We take it off when we go offshore so she's effectively engineless while crossing oceans. We only use the engine to get in an out of harbours marinas and mooring fields if it's a tight fit or illegal to do so. The motor is mounted in such a way so that there's not a single hole in the boat because of it.

We have been using this configuration for about 5000 miles now and it seems to be practical without taking away too much from the way she sails. We don't like using the motor and use is sparingly.

Does that answer your question?

Sounds like a rational way to cruise the boat and still keep in its history.