Swell Energy, Height, and Period...What's more important from a kayak

Hi,

Most of the time, when I fish in the ocean, I just look at swell height and period.  I typically target 3-4 ft at 8-10 sec which is my comfort range.  Recently I notice swell energy too but haven't really compared it so I don't know how it affects fishing from a kayak.

For instance, take the following two days...which is better for fishing from a kayak
Day 1) 3.4 ft @ 13 sec., swell energy = 400 KJ
Day 2) 4.7 ft @ 6.4 sec., swell energy = 165 KJ


Thanks

I don't pay much attention to swell energy, personally.  I think the swell energy matters more for surfing because that energy is being dissipated against the shoreline and correlates to how "rough" the surf is.  On the open ocean, the energy is constant on either side of the wave, it's not being transferred to your kayak in meaningful ways.  You're mostly floating atop the wave and your kayak isn't absorbing much energy.  I care more about period than I do swell height (to a certain degree).  I'll take a 10' swell at 20 seconds over a 3' swell at 3 seconds. 

I don't pay much attention to swell energy, personally.  I think the swell energy matters more for surfing because that energy is being dissipated against the shoreline and correlates to how "rough" the surf is.  On the open ocean, the energy is constant on either side of the wave, it's not being transferred to your kayak in meaningful ways.  You're mostly floating atop the wave and your kayak isn't absorbing much energy.  I care more about period than I do swell height (to a certain degree).  I'll take a 10' swell at 20 seconds over a 3' swell at 3 seconds.

+1 

A 5' swell at 20 seconds has more energy than 5' at 10 seconds. 20 seconds is more comfortable to fish and more energy hitting the beach when you launch or land. If you wipe out on an exposed beach it might be more meaningful.

I was under the impression that a wave with higher kilojoules has more mass and therefore more difficult to punch through at launch and more difficult to maneuver on landing...hmmmm....

A 5' swell at 20 seconds has more energy than 5' at 10 seconds. 20 seconds is more comfortable to fish and more energy hitting the beach when you launch or land. If you wipe out on an exposed beach it might be more meaningful.

I was under the impression that a wave with higher kilojoules has more mass and therefore more difficult to punch through at launch and more difficult to maneuver on landing...hmmmm....

Solid points... I've been doing too many easy launches and wasn't thinking of surf launches.  Wave energy matters as much for surfing as it does for kayak surf launches/landings.

A 5' swell at 20 seconds has more energy than 5' at 10 seconds. 20 seconds is more comfortable to fish and more energy hitting the beach when you launch or land. If you wipe out on an exposed beach it might be more meaningful.

I was under the impression that a wave with higher kilojoules has more mass and therefore more difficult to punch through at launch and more difficult to maneuver on landing...hmmmm....

Solid points... I've been doing too many easy launches and wasn't thinking of surf launches.  Wave energy matters as much for surfing as it does for kayak surf launches/landings.

All surf launches are intimidating.  My max energy is 450-480

Most of the time, when I fish in the ocean, I just look at swell height and period.

Me too, but clearly that does not tell the whole story. Today, for example, I fished Santa Cruz (where else?) and the prediction was S (or SSE) swell, 2' @ 16 seconds. A long period  southerly swell in SC means that it will surely be noticeable, but 2' is not that big, and 16 seconds is not that long, so I thought it would be moderate, swell-wise. But, it was miserable, with regular big roller-coaster style swells, random short period steep swells, and a choppy wind swell on top of all that. I survived nearly 7 hours, but only because I don't get seasick (that's my story, and I'm sticking to it...). It also helped that the fishing was good. However, now that I'm at home, that swell continues to play in my head...

Anyways, I think the question as to what is important, swell-wise, is not easy to answer. Lots of factors come into play.

Most of the time, when I fish in the ocean, I just look at swell height and period.

Me too, but clearly that does not tell the whole story. Today, for example, I fished Santa Cruz (where else?) and the prediction was S (or SSE) swell, 2' @ 16 seconds. A long period  southerly swell in SC means that it will surely be noticeable, but 2' is not that big, and 16 seconds is not that long, so I thought it would be moderate, swell-wise. But, it was miserable, with regular big roller-coaster style swells, random short period steep swells, and a choppy wind swell on top of all that. I survived nearly 7 hours, but only because I don't get seasick (that's my story, and I'm sticking to it...). It also helped that the fishing was good. However, now that I'm at home, that swell continues to play in my head...

Anyways, I think the question as to what is important, swell-wise, is not easy to answer. Lots of factors come into play.

Also Santa Cruz had a primary swell of 2'@16s, a secondary swell of 1-2'@18s, and a tertiary swell of 3.5'@8s.  Primary and secondary were out of the SSW and tertiary was out of the W.  So, swells about 90 degrees offset from each other definitely make it snotty.  Pile all 3 swells up at the same time and you have upwards of 7.5' swell.  Then add in the wind waves you mention and you have a sporty day.

Everything matters, just in different ways. Once you are out in the open water past any effects from rocks or reefs, swell height and period determine your ride. In general if the period is more than twice the height (like 4 ft at 8 sec) it will be easy to ride - as long as that is the only sea. If there is a secondary or crossing sea, it gets complicated. I once went out on a 47' charter boat when there was a "stacked swell" - two systems, one 8 ft at 16 sec and one 8 ft at 8 sec, both from almost the same direction. That resulted in the occasional 16-foot wave and a very wild ride even in a big boat. Either system by itself would have been much easier to deal with.

Once you get inshore and over a variable-depth bottom, the energy starts to matter. A low-amplitude long-period swell (e.g. 2 ft at 16-20 sec) can be very dangerous because it will break at irregular intervals over submerged rocks. It can also pile up into a big shore break, and sometimes produces the "rogue waves" you hear about - there is so much energy in the swells that when two of them combine, they just keep going up the beach.

Direction matters too, for beach launches and landings, even in protected coves. If the swell is running straight in it will create a lot more shore break than you might expect. A short-period swell running up a long inlet will usually dissipate its energy and leave you with an easy launch; a long-period swell in the same spot can make things very exciting.