Downwind and riding waves.....

[NewportNewbie]

Being new to sailing I am wondering if this is unique to my boat or common to all boats. When sailing downwind, waves come under the boat and for a moment the boat will "surf" on the wave, then the boat will slide down the back of the wave. The entire time the boat just seems a bit "squirrely" and doesnt feel very planted at all. The boat seems to swim left and right...never really straight...its kind of an odd and unpleasant feeling. Should I sail less direct down wind and more at an angle? Would that reduce this issue? I assume I am planing to some extent at that point? Someone who owns one of these boats did tell me it can be a handful downwind...is this what they were talking about?

[Faster]

That's the 3 dimensional environment you're in.. very different from driving on a road!

What you're describing is quite normal... different hull shapes will react perhaps differently in the same conditions, but this is where a good, attentive helmsman can make the difference in how the boat tracks and feels in that circumstance. The 'rush' of the downhill slide is what many are chasing when sailing in bigger seas.

As an IOR influenced design of the 70s any reference to being a 'handful in a breeze' is likely referring to the skittish behaviour these boats exhibit when pushed too hard under spinnaker - issues certainly made worse by the yawing introduced by a following sea.

Once you've got some practice you'll get to 'feel' the rudder load and unload - reacting to these sensations can help you correct slightly ahead of the boat's response - you'll be 'pre-acting' rather than 'reacting' and you'll end up steering a straighter line. In these conditions with a well balanced rudder I think a tiller is better than a wheel...

[smurphny]

+1 what Faster said. Also remember that if a following sea gets large enough and starts to break, it can broach you. Broaching is when the bow digs in, surfing down the face of a large wave and throws the stern around down the face of the breaking wave causing the boat to be beam-on to the breaking sea. This can very easily happen in an inlet with waves heaped up and breaking with an opposing current. It is something to be very aware of.

[Rockter]

You are normally moving fast in such conditions, and on a heavier ship (my own with a long keel), it is the best of good sailing.

The ship does tend to squirm a wee bit, but so far, she has never threatened to round-up on me and that included a trip right across the North Atlantic.

Maybe I just got lucky.
.

[zz4gta]

+1 to what faster said. Surfing waves can be a handful in breeze, but at the same time, it's some of the most fun you can have on a sailboat. As the bow starts to point down (the stern lifts up) gradually turn the boat toward ddw. Don't turn it DDW, just drive a little deeper. This will unload the rudder a bit, and with practice you'll be trying to stay on a wave face as long as you can.

I've been over 12 kts many times under chute, sometimes under a reefed main and #3, even hit 14 kts on a delivery once. However, my boat is quite a bit more stable than an IOR design. Basically, anticipate what the boat will do, and steer early to keep a wave from catching you off guard and rounding you up.

[NewportNewbie]

Thanks! Its not that I am moving very fast at all...maybe 6 knots...not under spinnaker...just wanna know the dangers if I am in that scenario.

[WDS123]

Newport,

Delighted to hear this !

FYI - It is customary to yell 'hooh-yah' or similiar cry of joy when surfing. Helps the passengers understand this is fun !

The S30 loves to surf, nearly impossible to truely plane the boat ( even thought people will tell you they have planed )

Yes is does feel squirrly at first, but eventually you'll be trying to surf every time you broad reach muttering under your breath 'come on come on baby get up'

[killarney_sailor]

You got the description right the first time - you are surfing and it can be quite fun in moderate conditions. If it gets to be too nasty you can reduce sail area to slow down.

Planing involves the boat sailing fast enough to rise on top of its bow wave and so is wind-dependent. As was pointed out, this does not happen very often with a displacement hull. It is also why most powerboats have very powerful engines so they can get 'up on the plane'. Surfing depends on boat wind force and gravity when you are sliding down the wave so is pretty common and not to be feared in normal conditions. Both surfing and planing although you to go faster than your boat's theoretical hull speed which is usually around (if I remember!) 1.34 x sq rt of LWL in feet.

[jackdale]

Broad reaching in enclosed waters with flat seas is a breeze compared to broad reaching in 12 to 15 seas.


A round up from a broach reach in flat water can have consequences, but they are nothing compared to a slam which will result from a round up in the ocean waves.

But there - below both times.

[BarryL]

Hey,

My only comment regards steering when sailing downwind. When a wave lifts the stern it can push the boat a little port or starboard and that will change the direction the boat is moving. Novices tend to overcompensate and start driving all over the place. My boat does better if I slow my steering inputs down. When the stern digs back in the boat will come back on course. Just be patient and let the boat move through the water.

Now, if you're sailing down wind in a big breeze you must be careful to not let the boat start to round up. When that happens the apparent wind increases quickly and that will want to make the boat head up, which increases the wind even more and so on. So you must be forceful on the helm to keep the boat sailing down.

Just get out there and sail. The more experience you get the better a sailor you'll become.

Good luck,
Barry