Question about long period swells

Okay, I have always been unclear on how to gauge swell forecasts. Generally I like to see a 2-3 ft swell every 10 seconds. That always results in flat surf.

But what about 2 ft every 23 seconds? I ask this because that is the forecast for Bolinas for Friday, starting around noon.

I realize 2 ft swell is tiny when you're on the water, but at a 23 second interval, can't that make for a dicey launch every 20 or so minutes?

-Andrew

Okay, I have always been unclear on how to gauge swell forecasts. Generally I like to see a 2-3 ft swell every 10 seconds. That always results in flat surf.

But what about 2 ft every 23 seconds? I ask this because that is the forecast for Bolinas for Friday, starting around noon.

I realize 2 ft swell is tiny when you're on the water, but at a 23 second interval, can't that make for a dicey launch every 20 or so minutes?

-Andrew

If you can’t clear the surf in 20 minutes you need a smaller boat ! 
It’s all about timing jump an paddle/peddle between swells, on the way out you should be able to punch through the wave and on the way back just ride it in azz over plastic with your gear lashed down... the spin cycle isn’t that bad unless your in a rocky area.

Think of a cross section of the wave - 2 @ 23 is huge volume of water under the peak and reaching out toward the 0 and 23 second mark.  All of that potentially "stacks up" on reef and shore features.  Definitely beware!

This weekend's swell is no joke.  Saturday has 10 @ 20 forecast up here. I'll just leave the ocean to the surfers in those conditions.

I need to find a good Youtube tutorial on swell forecast interpretation!

Sent from my SM-N920T using Tapatalk

Swell periods are tricky to understand. Simply put - the longer the period, the bigger and more powerful the waves will be. It gets even more complicated when you look at swell direction and the relation to the area you are planning on fishing. A rule of thumb that I learned about on this forum that I think is a really good go-to (especially for beginners) is that if the combined foretasted swell height and period add up to over 20, it's a no go. Personally, I'm getting gun shy at anything over 15 seconds, especially if the swell is out of the North West or West.

I need to find a good Youtube tutorial on swell forecast interpretation!

National Geographic used to have a wave/swell simulation online, but either it's gone or they moved it.  If I can find it again, I'll post the link.

Swell period is the time it takes for a swell to move past a stationary point, measured from trough to trough.

In general, in OPEN WATER, 2 feet @ 20 seconds is like flat water, but it has entirely different characteristics in the surf zone.

And here it is:

https://www.nationalgeographic.org/media/wave-simulator/

In general, in OPEN WATER, 2 feet @ 20 seconds is like flat water, but it has entirely different characteristics in the surf zone.

This ^^^^^^

Think of a cross section of the wave - 2 @ 23 is huge volume of water under the peak and reaching out toward the 0 and 23 second mark.  All of that potentially "stacks up" on reef and shore features.  Definitely beware!

Good description.

Think of a cross section of the wave - 2 @ 23 is huge volume of water under the peak and reaching out toward the 0 and 23 second mark.  All of that potentially "stacks up" on reef and shore features.  Definitely beware!

Good description.

Follow it to its logical extreme, a tsunami wave is about a 2' wave with a 1200 second period.

Follow it to its logical extreme, a tsunami wave is about a 2' wave with a 1200 second period.

RUN

For surf launches, personally it usually comes down to this question, "Would I be willing to go X feet of wave twice in successions and will I survive to fish?" 

For the first part, that means the punches, wet, and be able to keep going.

For the second part, that means I will have enough gear to fish on after a dump, in reasonable condition (i.e. warm enough), and have plenty of energy to survive another catastrophe.

Most of the time, if I am already at the beach, I launch.

All good info, thanks. Most of my launches these days are HMB harbor or Linda Mar on calm days.

In the TI, a bad launch or landing is far worse than in a single-hull kayak; all sorts of things can break (rudder, ama, mirage drive), and a capsize would be catastrophic, relatively speaking. Hence my questions.

In the TI ...

A whole different set of parameters apply to AI/TI launching (and especially landing).