How to avoid rounding up whilst sailing downwind
- Thread starter maxmonk
- Start date
Iain C
Well-Known Member
My 2p worth...there's a lot of science being quoted here, which is probably all very true, however you also need to keep things at a simple, practical level.
Clearly you are over canvassed unless you are doing something really wrong with trim. If you are single handing, you need to be powered up in the gusts, not the lulls. If you were fully crewed or a ninja helm, you might be able to nudge that "fully powered" point further down the wind range, but I guess you need to sail a bit more conservatively.
It sounds like you are starting to learn your boats behaviour (and I hope that doesn't sound patronising). A good mate who I have sailed skiffs with for years, plus yachts, recently both sailed at separate times on a mate's new racey 42 footer. We both came to exactly the same conclusion, you need to reef much earlier on that boat (with it's powerful sail controls, big wheel and spade rudder) than you do on my ploddy old tiller steered skeg ruddered MAB. Reefing early on your boat might still have you closer to the red line than a boat with you who is still fully canvassed. That other boat might also have over a quarter of a ton of people, five foot away from the centreline...that's only a few people but one hell of a lot of righting moment compared to you on your own.
I'd also really recommend some time on the stick of a really high performance dinghy in some decent breeze. You may think you are heading low enough, or that your boat is flat, or you are making enough course corrections or that you are easing the main quickly enough, but you may well not be. To give you an idea, my 49er has a rudder about the same size as a Laser, if it heels more than about 15 degrees the wing is in the water and you will swim, you can't steer with any more than about 15 degrees of heel on, and you are carrying the same sail area as a twenty something foot cruiser in an unballasted boat two of you can just about pick up. It soon gets you thinking about what is going on above your head and under water. Skiff sailing golden rule...keep the boat under the rig. Granted there's a lot of other stuff going on like proper apparent wind sailing etc, but a session in something like that will keep you on your toes and it will make you a better big boat driver.
The RTIR is a case in point...you see a gust coming, some boats around you crack off, ease sheets, open leaches, flatten off and go...others do too little, too late, with the inevitable spin.
Also, is your rudder nice and clean or covered in weeds and barnacles?
Good luck!
Clearly you are over canvassed unless you are doing something really wrong with trim. If you are single handing, you need to be powered up in the gusts, not the lulls. If you were fully crewed or a ninja helm, you might be able to nudge that "fully powered" point further down the wind range, but I guess you need to sail a bit more conservatively.
It sounds like you are starting to learn your boats behaviour (and I hope that doesn't sound patronising). A good mate who I have sailed skiffs with for years, plus yachts, recently both sailed at separate times on a mate's new racey 42 footer. We both came to exactly the same conclusion, you need to reef much earlier on that boat (with it's powerful sail controls, big wheel and spade rudder) than you do on my ploddy old tiller steered skeg ruddered MAB. Reefing early on your boat might still have you closer to the red line than a boat with you who is still fully canvassed. That other boat might also have over a quarter of a ton of people, five foot away from the centreline...that's only a few people but one hell of a lot of righting moment compared to you on your own.
I'd also really recommend some time on the stick of a really high performance dinghy in some decent breeze. You may think you are heading low enough, or that your boat is flat, or you are making enough course corrections or that you are easing the main quickly enough, but you may well not be. To give you an idea, my 49er has a rudder about the same size as a Laser, if it heels more than about 15 degrees the wing is in the water and you will swim, you can't steer with any more than about 15 degrees of heel on, and you are carrying the same sail area as a twenty something foot cruiser in an unballasted boat two of you can just about pick up. It soon gets you thinking about what is going on above your head and under water. Skiff sailing golden rule...keep the boat under the rig. Granted there's a lot of other stuff going on like proper apparent wind sailing etc, but a session in something like that will keep you on your toes and it will make you a better big boat driver.
The RTIR is a case in point...you see a gust coming, some boats around you crack off, ease sheets, open leaches, flatten off and go...others do too little, too late, with the inevitable spin.
Also, is your rudder nice and clean or covered in weeds and barnacles?
Good luck!
jwilson
Well-Known Member
Everything he said is right, but keeping the boat under the rig is the key - steer to put the hull back underneath the mast, preferably just before the gust hits. Applies to everything from dinghies to big cruisers when offwind and on the limits of normal control.
dom
Well-Known Member
Javelin
Well-Known Member
Er don't want to be picky here but sailing a 49er dead downwind in 20knts is almost impossible !
However I do understand and support your theory.
To OP;
Your hull speed is a little over 6.5 knts
In 15knts apparent with a full main you should be doing that or pretty dammed close.
Which means the true windspeed will be more like 20knts
If you are at hull speed and you get a gust the boat either has to go faster (surf) or it will force the bow down and slow the hull and broach.
Any weight forward like deflated dinghy, anchor chain, wet sails etc will make it more likely to broach and less likely to surf.
If you anticipate you can ward off the broach with the rudder but you really have to be on the ball.
If like me you use a tiller pilot they only react and can't anticipate so again your more likely to broach.
If you have a fixed prop remember that your rudder is in disturbed flow so will be less effective.
In summary you should be ok up to 6 knts through the water - anything above that then you're starting to push your luck, so reef.
However I do understand and support your theory.
To OP;
Your hull speed is a little over 6.5 knts
In 15knts apparent with a full main you should be doing that or pretty dammed close.
Which means the true windspeed will be more like 20knts
If you are at hull speed and you get a gust the boat either has to go faster (surf) or it will force the bow down and slow the hull and broach.
Any weight forward like deflated dinghy, anchor chain, wet sails etc will make it more likely to broach and less likely to surf.
If you anticipate you can ward off the broach with the rudder but you really have to be on the ball.
If like me you use a tiller pilot they only react and can't anticipate so again your more likely to broach.
If you have a fixed prop remember that your rudder is in disturbed flow so will be less effective.
In summary you should be ok up to 6 knts through the water - anything above that then you're starting to push your luck, so reef.
Laurie
Well-Known Member
PeterR
Well-Known Member
There has been a lot of good advice about boat handling. However, having sailed many boats over the years there have been a few that become totally uncontrollable under the circumstances you describe and there simply is no option but to reef or go to just a headsail.
However, if you are in the close quarters situation you describe - hit by a gust and unable to round up without T-boning other yachts - one thing you can do as a short term measure is trip the main halyard. The sail will not come down – too much pressure – but the head of the sail will drop a little. Just that small drop is enough to take the tension out of the leach and dramatically reduce the tendancy to round up. This seems to have more effect than easing the kicker as the head of the sail is totally depowered. It really more nearly equates to scandalising the main but that takes longer on any boat and is nigh on impossible on boats with a rod kicker.
This trick also works if you have run aground on a leeward shore and need to gybe to get the boat pointing in a suitable direction to get off again. In a strong wind the main will overcome all efforts of propwash on the rudder to make the boat spin but after a quick ease on the halyard propwash wins and you are off and sailing again.
However, if you are in the close quarters situation you describe - hit by a gust and unable to round up without T-boning other yachts - one thing you can do as a short term measure is trip the main halyard. The sail will not come down – too much pressure – but the head of the sail will drop a little. Just that small drop is enough to take the tension out of the leach and dramatically reduce the tendancy to round up. This seems to have more effect than easing the kicker as the head of the sail is totally depowered. It really more nearly equates to scandalising the main but that takes longer on any boat and is nigh on impossible on boats with a rod kicker.
This trick also works if you have run aground on a leeward shore and need to gybe to get the boat pointing in a suitable direction to get off again. In a strong wind the main will overcome all efforts of propwash on the rudder to make the boat spin but after a quick ease on the halyard propwash wins and you are off and sailing again.
Laurie
Well-Known Member
LadyInBed
Well-Known Member
When stuck, effectively out of control, I quite like that idea.
Perhaps the only other action to help maintain directional control is to deploy a drogue.
fergie_mac66
Well-Known Member
+1 on both