What is considered unsafe sea condition?

While I'm new to kayak fishing, I'm not new to the ocean, and the one thing that consistently amazes me is just how unpredictable conditions on the California coast can be (and yet therefore, also fairly predictable).

I think yesterday was a prime example of how things aren't always as they might seem based on internet reports (since the data is rarely from your specific spot).  I had decided to head up to either the Salt Point area or north of Point Arena as swell was called as being moderately mild in the morning ~5ft @ NWN and low wind and hid tide at ~10am.  However, there was then a large gap in data during the day, and the night it was calling for 10+ foot swells from WNW, and I've got a brand new unfamiliar kayak sitting in the garage, and so I decided I wanted to play it safe. 

Instead, I found it to be nearly dead flat all morning south of Stump Cove, perfect conditions and I hit myself for not bringing the kayak.  However, north of Stump Cove, waves were hitting 10-15 feet and every 2-3 minutes a sleeper would enter the cove with devastating force.  On my drive back home down through Carmet and north of Bodega, there were massive massive breaks. 

Since I'm still usually hanging out in somewhat protected areas that aren't exposed to the offshore swell, if the swell is 6-8 feet but NWN or NNW and with a mild tidal change, many of the launch areas and coves are often quite flat.  But a WNW or W swell at even just 3-4 feet can make some entries and exists a total nightmare, especially at low tide. 

What helped me the most was just checking out the entry/exit spots and the areas you want to go, as often as you can, in as many conditions as you can, and compare them to what is being reported or predicted (even if you are just driving by or going for some other activity).  Spending 3+ days a week on the Sonoma Coast the last 10 months fishing and exploring every nook and cranny has left me feeling very confident that I can predict conditions, but often that means simply predicting that they can and will change. 

What I don't understand yet is how much period affects things.  Seems like an especially short period could be just as bad as a long one. 

What helped me the most was just checking out the entry/exit spots and the areas you want to go, as often as you can, in as many conditions as you can, and compare them to what is being reported or predicted (even if you are just driving by or going for some other activity).  Spending 3+ days a week on the Sonoma Coast the last 10 months fishing and exploring every nook and cranny has left me feeling very confident that I can predict conditions, but often that means simply predicting that they can and will change.

This 100%.  As a long time surfer (but new kayak fisherman) there is no better way to learn what a swell will do at a given spot.  And it can be super different from one cove to the next, or with a small difference in height, period, or direction of swell.  Or tide.  As a side note I'm really enjoying "relearning" the coast I know so well from a surfing perspective through the fresh eyes of looking at kayak launching conditions.

What I don't understand yet is how much period affects things.  Seems like an especially short period could be just as bad as a long one.

Period is as big of a deal as height for wave energy when breaking.  Think of it as the horizonal measurement of a wave's cross section.  A long period 2 foot swell in the open ocean can create 6 foot breakers as it stacks up in shallow water.  Long period swells also wrap into areas better (e.g. a NW swell with a long period will be better able to maintain energy wrapping into a south facing beach), and are more impacted by bottom contour in terms of being refracted towards or away from any given place on the coast.  A good example is moss landing.  Because of the canyon and shallower water on either side, long period swells bend towards the shallower water, and long period swells often create smaller waves on the beach there than shorter period ones.  It is complicated, and the best way to learn is to watch your beaches carefully per above.

When on the water and past the surf, long period swells, even tall ones, are not a big deal because they are not steep.  They just feel like rolling hills on the water.  Short period swells, especially when they are tall or there are multiple swells from different directions, are what are harry on open water.  They are steep and choppy and can be destabilizing.

This is a massive and super deep topic, but those are my thoughts off the top of my head!

What I don't understand yet is how much period affects things.  Seems like an especially short period could be just as bad as a long one. 

I think the best way to conceptualize the affect that the wave period has is to think of it in terms of the energy of the wave.  Longer period swells bring a whole lot more energy with them.  Taken to the logical extreme, a typical tele tsunami wave from a large subduction zone earthquake is a 3 foot wave with a 1200 second period.

What I don't understand yet is how much period affects things.  Seems like an especially short period could be just as bad as a long one. 

I think the best way to conceptualize the affect that the wave period has is to think of it in terms of the energy of the wave.  Longer period swells bring a whole lot more energy with them.  Taken to the logical extreme, a typical tele tsunami wave from a large subduction zone earthquake is a 3 foot wave with a 1200 second period.

That's why I like surf-forecast.com, it tells the energy, kilo Joules of the swell/waves, I can launch in up to 400, Monday night is reading 11,110.  Swell reading is 13ft @ 20 sec.

What I don't understand yet is how much period affects things.  Seems like an especially short period could be just as bad as a long one. 

I think the best way to conceptualize the affect that the wave period has is to think of it in terms of the energy of the wave.  Longer period swells bring a whole lot more energy with them.  Taken to the logical extreme, a typical tele tsunami wave from a large subduction zone earthquake is a 3 foot wave with a 1200 second period.

That's why I like surf-forecast.com, it tells the energy, kilo Joules of the swell/waves, I can launch in up to 400, Monday night is reading 11,110.  Swell reading is 13ft @ 20 sec.

Fantastic.  I need to start data tracking that as well. 

Now that you guys have jogged my memory, I remember I had to learn all about this for my scuba divemaster course years ago.  But living in the tropics with a protected reef at my front door, definitely wasn't needed! 

I certainly assumed a larger period was worse, but now it's "duh...". 

I would say longer period is mostly worse for a surf launch, because longer period = more energy.  But there is nuance.  Long period waves hit the coast with more uneven breaker size because long period waves diffract more as they interact with the ocean floor, and thus concentrate at certain places which "steals" wave energy from other places. 

Also long period swells are way more manageable once you are out of the surf zone.  5' at 6 sec is potentially super dangerous wind chop that can beat you around on the open water, 5' at 20 sec (with no additional wind swell) is long rolling hills that are no problem if you have a sheltered launch of some sort and don't need to deal with that swell breaking in the surf zone.

So longer period = more energy, but like all of life, it's complicated! 

The best thing you can do is check conditions as much as you can.  This is obviously easier the closer you live to where you fish.  Then compare what you see with the forecasts.

Compare different sites to see which is more accurate.  I've found that different sites are more accurate for spots than others.  It helps to understand where the forecasts are getting their data and how they are interpreting it.

Some sites may be accurate on wind, but less surf size.

For instance, I like Magicseaweed for surf size, but WillyWeather for wind.  But WillyWeather is more accurate for wind when the wind data is coming from an area closer to the spot.  HMB wind comes from the airport right there, where as Pacifica wind comes from SFO.  It seems complicated at first but the more you study the better you can guess if the day is right to go.

When forecasts very a lot for the same day, be ready for changing conditions.

The only advantage I find in a longer period swell is that the lull is when you launch.  Predicting it is the risk, when it's go time you go...hopefully it's the right time...

Great thread!!!

Yes it is Sledge. Hope all is well.
Even here in Texas and on small > 50 acre lakes the wind can some a howling fast. A lot of non-experienced kayakers get stranded and have no clue or energy to paddle back. I see it happen a lot and warn them about when the wind hits since I look at four different weather sites before heading out.

Like I learned from NCKA you only have a certain time to get out and head in before the wind blows. I brought that training wit me to Texas and still live by it.

Reviewing the forecasts and learning how to read the ocean is only one of the inputs to a risk formula. Your skill and gear also matter. For example, to deal with kayak separation in wind, I have a coiled cord with carabiners that I use to attach myself to the kayak, but only when wind is strong, and when I’m by myself. Otherwise it could be a strangling hazard. This makes me comfortable taking more risk. As another example, I also have a spare battery for my radio, so say if I get swept far, I know there’s enough juice in there.
A third example is my packing strategy. If you see me launch and land you’d never know it’s a fishing kayak because everything goes into dry bags or storage and under bungee cords. So I can accept riskier launch and landing.
All of those things I learned from fellow NCKA members.

For those interested in a scientific description of various wave behaviors  I recommend Willard Bascom “Waves and Beaches”.  It’s technical, but still readable, and entertaining.  His early research included measuring beach profiles on the Oregon Coast with a lead line from a “Duck Boat” (military surplus landing craft).  Kind of a geeky read, but explains a lot.  Enjoy!

Loving the perspective of the board surfers on this thread.  Thanks for that.

Scored some thigh straps, step one, practice,  step two, vision, getting barreled on my Kraken, step three.  Easy peasy chicken dinner!

 

I started wearing a helmet for surf launches 3 seasons ago and I don't care what anybody thinks.  I had a scare on the ski slopes and it made me think I should probably wear a helmet in a lot more situations.