My AWB achieved Hull Speed - What did I do right?

[Paulfireblade]

Firstly clarify it was 7.1 knots through the water.
To be fair it only topped 7 knots briefly but was managing 6.8 solidly on a close to beam reach in 20-24 knots of wind on Friday.

I normally am happy to get over 5 Knots in that sort of wind.
So what was I doing right/differently.

I sail from Shotley and normally head south down the wallet which can be a bit choppy but this time I headed north as wind and tide directions were favourable so headed for Hollesley bay just past Orfordness so only about 14 miles from Land guard Point.

1.seastate was fairly calm
2.antifouled 8 weeks ago, better brand
3 . Three reefs on main and one reef Genoa
4.Main sheet was a bit tighter than normal for that point of sail than I would normally do.

So where did nearly an extra 1.5 knots come from, be good to know so I can replicate as it was pretty satisfying moving along at that speed???

Also part of the way back I was really pinching the wind to minimise tacks and could get to 30 degrees off the wind before sails luffed, obviously speed dropped dramatically that close to wind but as sailing single handed made tacking easier as I just had to press autopilot 10+ button six times and then grab the Genoa sheets.

All in all very impressed with my old French floating caravan albeit she has a fin keel and decent Kemp sails. A satisfying days sailing for this newbie.

 

[Frayed Knot]

It’s a good feeling when you get your boat sailing really well, isn’t it?

There are probably several factors, some more tangible than others…
Being well reefed probably means your sails were flatter, suiting the fresh conditions, & you were sailing relatively upright - lots of us waste the energy of the wind with excessive heeling which only suits older, traditional designs - my old, narrow long keeler sailed like a witch with her rail under but modern boats want to gripe & tend to develop weather helm which causes drag.

A friend with a Bav 32 exchanged his standard 135%ish genoa for one of around 115% & the boat was transformed - faster to windward & achieving a good extra 10 degrees performance & with very little speed loss off the wind. Since he told me about it, unless conditions are very light I now put a couple of rolls in mine when beating & experience similar results.

The less tangible bit is getting a feel for your boat. Even though I’ve been sailing for about 45 years I’ve found that when I’ve changed boats (I’ve had the current one for 5 years) it’s taken several seasons to develop each time. At first I would be a bit disappointed but after a season or two, each time I sailed I would find the boat performed better & better but I really couldn’t put my finger on why. This has been the case with the 3 boats I’ve had over the last twenty or so years.

 

[Paulfireblade]

Really appreciate the insight @Frayed Knot and wow 45 years, sadly discovered sailing fairly late having only been sailing 3 years and had my boat 18 months but will likely be my first and only so hopefully will get to know it really well over that time.

 

[johnalison]

I sometimes amuse myself by wondering how many hp the sails are producing on a good day when I can go a good know faster than my 27hp engine. 7 knots is not hard to achieve on the water log and I can sustain it often quite easily, but it is much harder to do so over a passage, since every few seconds below that speed drags down the average. With so much wind you should have all the power you want, but I sometimes find that adjustment to the sail shape and position of the main can give or take half a knot or more, as well as making the handling more balanced and pleasant.

 

[Daydream believer]

Would the OP like to tell us what sort of boat it is.
How has he calibrated his log for 6+ knots?

 

[johnalison]

Would the OP like to tell us what sort of boat it is.
How has he calibrated his log for 6+ knots?

Give the poor lad a chance. It’s actually quite difficult to calibrate a log properly and even then it won’t suit all conditions. Mine under-reads at low speeds and over-reads at higher, so I usually try to get it right for 6.5 knots, but even then, it will vary according to whether I’m sailing or motoring and also according to the depth if <5m. I’m going to assume his speed perhaps less 5% because I’m in a good mood.

 

[Paulfireblade]

Thank you @johnalison and as fairly new to this I am trying to understand where the extra speed came from on the day as I have sailed before in the same wind speeds.

I am cruising in a Jeanneau Sun Odyssey 34.2

My Navionics provides an SOG and the difference between SOG and the speed log is normally very close to the known tidal rates provided by the UKHO Tidal stream atlas so that is good enough for me and it might read high but the increase in speed is still a significant percentage so my query remains the same.

I am not looking to enter Guineas book of records but interested to understand what worked so well on the day.

 

[Daydream believer]

Yes, you should be clocking between 7.69 & 8.23 if wind is 90 degrees actual which would be closer apparent
Orc sailboat data
So you still have a bit to find if only doing 6.8
But keep practicing. It takes a while.
3 reefs seems a lot.
I find the biggest killer is a dirty bottom

 

[Paulfireblade]

Interesting chart, didn’t know that sort of info would be available for a 20 year old boat.

As mentioned above in OP I was between close reach and beam reach So approx 67 degrees rather than 90.

Interested in you comment re dirty bottom, as mentioned in OP recently antifouled with a better quality paint.

So probably a combination of different things led to the increase in speed achieved.

 

[jimi]

Used to have a Bennie 331 and passage planned at 6.5 knots.. often arrived earlier!

 

[Concerto]

Personally I feel you are asking the wrong question. You should be asking "What am I doing wrong most of the time whilst sailing to be going so slow?"

Sailing fast is a combination of many factors. It is a steep learning curve that can be made a lot simpler if you learn how to use the tell tails on your sails - if you have none then fit them immediately. An accelerated to way to learn how to sail fast is to go racing on a performance boat.

Try watching some of the videos in this google search.
how to set sails on a yacht - Google Search

I sail a 1980 32ft Westerly Fulmar. She has fairly new sails and I have been sailing since 1965 including a lot of offshore racing. Lots of people say I have a quick boat, but in reality I try to sail at least 90% of the possible speed. Despite sailing singlehanded I regularly sail with 35 or 36ft AWBs with full crews. I see so many badly set sails, I know they are only obtaining 60 to 70% of their potential, so keeping up with them is easy.

This summer I met up with a Westerly Storm, a slightly faster boat than mine. On several days I just walked away from them and will shortly be going aboard to teach them how to improve their performance by correctly setting the sails.

 

[xyachtdave]

Hey Paul, when you say you’ve been out in the same wind speeds before, don’t forget cold damp air has more weight behind it than the same dry, warm air in summer.

This additional speed could be as simple as this extra pressure rather than any difference in sail trim. I’m assuming you’ve not adjusted anything new or more than you would normally?

Getting the best out of your boat is fun, but occasionally when I’m making lunch, or sailing with friends, maybe fishing or letting a novice run the boat while I relax, you come across someone hell bent on getting past you, desperate to prove themselves.

At this point, depending on who it is, I may make more of an effort!

 

[Daydream believer]

Used to have a Bennie 331 and passage planned at 6.5 knots.. often arrived earlier!

And so you should. I notice that in 12kts just about every angle of wind a 331 should easily exceed 6.5 kts.
Anything less would be a disgrace
331

 

[jimi]

And so you should. I notice that in 12kts just about every angle of wind a 331 should easily exceed 6.5 kts.
Anything less would be a disgrace
331

Flat water obviously!

 

[Daydream believer]

Flat water obviously!

The figures are used over a wide variety of conditions, to establish the ratings for racing.
Sorry! you have no excuses. In fact with a decent passage plan, using the tides, one should be able to blitz these figs over a typical coastal passage.

 

[Paulfireblade]

Used to have a Bennie 331 and passage planned at 6.5 knots.. often arrived earlier!

I was obviously in ignorant bliss, I had no idea my boat could go any faster. RYA courses major on safety but not much time spent on sail trim and the theory courses don't help with boat speeds of 5 knots often used for practice course to steer questions so that perhaps set my expectation

 

[Paulfireblade]

Hey Paul, when you say you’ve been out in the same wind speeds before, don’t forget cold damp air has more weight behind it than the same dry, warm air in summer.

I knew colder air gave more BHP in an internal combustion engine but did not know it made a difference with sails, interesting.

 

[Tranona]

I was obviously in ignorant bliss, I had no idea my boat could go any faster. RYA courses major on safety but not much time spent on sail trim and the theory courses don't help with boat speeds of 5 knots often used for practice course to steer questions so that perhaps set my expectation

5 knots passage plan is still valid for many average 30-35' boats because in mixed conditions it is difficult to keep up with the theoretical speeds available in flat water and a free wind. However with careful planning to make full use of the tides, favourable winds and well trimmed sails to exceed this by some margin. For example, one memorable passage from Cowes to Poole using a whole spring tide and a northerly wind (off the land which means flat seas) in a similar boat to yours (Bavaria 33) less than 4 1/2 hours or nearly 8 knots over the ground. Speed through the water rarely fell below 6 knots and mostly nearer 7. There are many ways of improving water speed and therefore reduced passage time, the most effective of which in my view is fitting a folding or feathering propeller which typically adds 0.5 of a knot in boat speed. So in a typical cross tide passage like Solent Cherbourg (65 miles or so) you can save around one hour.

 

[johnalison]

My boat's polar diagram gives about 7.5kn at 90 degrees to 14 knots of wind, but I have never been able to average anything like that over a long passage. If I am seeing 7-8 knots on the dial (log or GPS) most of the time, the average will usually be in the mid 6s, so I generally plan for 6 knots, assuming that I will use the engine if it drops much below that for an open sea trip.

 

[Daydream believer]

When I did my 2 round UK trips the average, inc time spent motoring in & out of port , & through the cally canal & locks etc. was a tiny fraction under 6 Kts. However, only 6 legs each time were over 100 miles, (thus tending to cancel tides) so generally I made sure that I was able to use the tide to my advantage.
As Tranona points out, that makes a huge difference to a passage time. Without using the tides (& waiting for favourable wind, with which I was usually lucky) my average may have been significantly less.