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    #16
    Originally posted by mike 3888 View Post
    Hay all, I was up all last night looking over weather wave and wind stuff. I have a few more questions that I really cant find a solid answer to.
    I understand the longer the frequency period is the more it will be like a swell; right?

    But what I cant find is at what point do swells turn in to chop and then waves?

    I am also guess winds can affect these too?

    example:
    say they report 4 foot with 4 second intervals is that where is gets rough? and for example for argument sake say we are heading south into the waves that are coming north. The winds are coming out of the north? to me this would seem to be a very rough ride? Am I looking at this stuff right???
    there is a lot of information concerning your question, and there are many books and online articles about waves, ocean swells, chop (small wind waves) and the many factors causing waves to break ..

    a swell is a wave, but of long length or frequency, and so to distinguish a long frequency wave from a short frequency wave, they are generically called a swell.... and they can be so long as to go un-noticed, and there can be a swell without any noticeable water disturbance at all... swells turn into waves as they get shorter in frequency and begin to take on definite form....

    in open water, waves begin to break when the height to length frequency gets near a ratio of 1 to 7.... BUT, any size wave can break at anytime, and/or it can be unusually large in relation to the conditions at the time, and these are called freak or rogue waves...
    the wind current wind speed and direction is a huge factor in how big the waves or chop is in the local area.... with the wind traveling faster than the wave, either against the direction of the waves or in the same direction as the waves, it can cause waves to break or spume to fly off the tops of waves without them breaking... as the wave approaches shallower water or a reef, it will also break..

    chop is small wind waves that have a small break at the top of them...they can happen in a small pond or on the ocean, and depending on the size of them in relation to the boat, they can be nothing more than a discomfort, or they can be very dangerous.....

    waves are caused by the wind somewhere in the world, and as the waves travel, they can move thousands of miles without any other wind pushing them, but the waves travel on.....

    as a person who has owned sailboats, and used the wind to advantage, I find the subject of wind and waves to be an interesting subject and have read many books about it, and also tides, which is another entirely different subject that has nothing to do with wind or waves, but can very dramatically add to the effects of the waves...as will current. there are a lot of variables that affect the way the water behaves in any given area.


    NU LIBERTE'
    Salem, OR

    1989 Bayliner 2556 Convertible
    5.7 OMC Cobra - 15.5x11 prop
    N2K equipped throughout..
    2014 Ram 3500 crew cab, 6.7 Cummins
    2007 M-3705 SLC weekend warrior, 5th wheel
    '04 Polaris Sportsman 700 -- '05 Polaris Sportsman 500 HO
    Heavy Equipment Repair and Specialty Welding

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      #17
      WOW ok between waves and inverters my mind is turning to mush. I am sure with time and a lot of guidance from you smart guys I will become a little more confident and hopefully a safer boater.
      Again want tell all thank you VERY interesting threads!!
      Mike and The Admiral Karen

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        #18
        Originally posted by mike 3888 View Post
        WOW ok between waves and inverters my mind is turning to mush. I am sure with time and a lot of guidance from you smart guys I will become a little more confident and hopefully a safer boater.
        Again want tell all thank you VERY interesting threads!!
        Mike and The Admiral Karen

        If yo haven't done so already, take a series of classes from the US Power Squadrons: https://americasboatingclub.org/lear.../power-boating
        1999 3788, Cummins 270 "Freedom"
        2013 Boston Whaler 130 SS
        Anacortes, WA

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          #19
          Originally posted by mike 3888 View Post
          We took Happy Happy (bayliner 3888) for our maiden voyage (for us good news is we didn't break anything!!! Now the questions: We went out the pass at destin fl they were reporting 3 to 4 foot seas. I did not feel unsafe but sure did not want to get out of the seat, a few things got knocked over but nothing serious. After 30 mins of this we came back in and spent the rest of a VERY nice day in the bay and ICW. What wave heights would you guys feel comfortable cruising in? Any suggestions on a good source to understand how to interpret Wave/weather - reports Looking forward to the upcoming weekend!!! Mike and the Admiral Karen
          You can get real time information from NOAA Buoys. This will include winds, etc., wave height and period like this one off Penscola https://www.ndbc.noaa.gov/station_pa...?station=42039

          Looking at this current data - I wouldn't want to be out there. 8' wave with a 5 second period and 31kt wind gusts.

          I don't mind any wave height as long as the period is long. a 10 foot wave with a 20 second period is actually fun.
          Irony
          1989 Bayliner 4588 - EH700TI
          Portsmouth, NH

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            #20
            I’m with Kwood. I would not venture out in the conditions indicated by the bouy he posted.. A good rule of thumb for your marine decision making is if the DPD is close to or less than the DWHT remain in the slip. For a new boater one might double the DPD compared to DWHT till one gains experience. Plus it’s really no fun getting beat up! Remember the DWHT is the average of the highest 1/3 of all wave heights. Thus if the bouy reports 6’ seas expect to see occasional higher seas. Here’s the descriptions page from the National Bouy Center:
            https://www.ndbc.noaa.gov/measdes.shtml
            Jim Gandee
            1989 3888
            Hino 175's
            Fire Escape
            [email protected]

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              #21
              I found DPD dominate wave period... what does DWHT stand for?

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                #22
                Jim what does DWHT stand for?

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                • Centerline2
                  Centerline2 commented
                  Editing a comment
                  see this https://www.ndbc.noaa.gov/wavecalc.shtml ...its only a short page, but may help to explain the confusion.... mostly it will allow you to see there are so many acronyms in the study of waves that you will only remain in a state of confusion if you attempt to remember more that a couple of them...

                • C-ya
                  C-ya commented
                  Editing a comment
                  Since DPD = dominant wave period, I would venture that DWHT = dominant wave height. All a new experience for me as well. I have to learn the weather of southern Lake Michigan. Wish I would have spent more time talking to the quartermasters and aerographer's mates when we were underway.

                #23
                Yes, WVHT = Significant Wave Height
                Jim Gandee
                1989 3888
                Hino 175's
                Fire Escape
                [email protected]

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                  #24
                  I would also toss this into the conversation. Because we own essentially pleasure crafts, there isn't an adequate method for the mass evacuation of water from the cockpit or deck areas. A cockpit scupper drain is not going to be able to handle the amount of water some seas kick up. Calm seas are more fun anyway!
                  "FOG 1"
                  1989 Bayliner 3288
                  Twin 305s
                  Kenmore, WA

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                    #25
                    Guys I think this has been a great Thread! heading down to what I hope will be much lower WVHT's with much longer DPD's and clam winds. Getting all this from both a general forecast and from the weather buoy. I am still wide open to leaning anything I can..
                    PS wish me luck getting the inverter to come on...

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                    • Centerline2
                      Centerline2 commented
                      Editing a comment
                      what inverter do you have.... mine also had problems turning on, and i found that I only had to press the ON button extra firmly to get it to activate....

                    • Pcpete
                      Pcpete commented
                      Editing a comment
                      Clam winds? Darnn spellcheck!
                      How is your inverter controlled? Do you have a remote switch? My inverter is mounted in the aft locker of the guest stateroom and I have a controller over the fridge. The 120 wires go to a designated switch on the ac panel that then feed the refrigerator, microwave and outlets. If the master if off, the inverter can be on, but no power will pass. Where does the inverter get the 12v? I have a dedicated bank of four golf cart batteries that connect to a big fuse then an off/on battery switch before going to the inverter. It makes for a good time to practice with your multi meter to make sure you have 12v in. The power wires weren’t disconnected for transport were they?
                      It may mean a call to the po to find the secret switch.

                    #26
                    my rule for going out is 3 foot average 15 knots of wind for my 27 foot cabin cruiser. If its bigger than that the wave periods have to be over 15 seconds. The best general advice I've read is you want 10 foot of boat for every foot of wave and find this a good rule.

                    I've been overnight at Catalina when an Earthquake hit Mexico a few days before, I couldn't get back so called into work and moored it, make sure you always have a backup plan and if SHTF I always carry a battery powered personel locator beacon, its a great relief to know I can press that button and in 30 minutes a helicopter will be there and hope to never need it.

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                      #27
                      Depending on the area you boat in, current ( tidal change ) and depth can also effect conditions. Here in Puget Sound, crossing the Strait of Juan De fuca can be a challenge for a 25-30 footer at times. We have crossed when the buoy was reporting 2 foot waves with a 6 second period. But when the water depth around the eastern bank got around 13 fathoms and the the tide was moving out against the west wind the seas were confused was a understatement. The buoy was west of us and not recording the conditions where we crossed which were more like 3-4 foot, 4 second from all directions. At 10 knots the 2452 handled it, but it was a hour of bobbing like a buoy. The wind was calm at 5 knots and a perfect mid summer July morning. Very deceiving just looking at weather forecast and buoy data. But we learned something that day. Straightest line to cross is not always the best.

                      Now we head west for about 20 minutes and cross west of the buoy where it is usually calm swell due to deeper water.

                      Toy4two - I used to Test Fly over those waters between Marina Del Ray , Long Beach and Catalina. We used to spot some HUGH sharks basking in the sun in that channel. Always had a raft on board . Feared them finding the beacon and just the arm that was holding it.

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                        #28
                        All, Had a great weekend up until the last two hours..
                        Weather and tide..found out at our marina *ECM an incoming tide with a southeast wind (10 to 12 knots) is NOT a good combo for back the boat into the slip. I tried 3 times and the marina Captains tried 5 times between them. We left her tied to the T dock at the end. The throttle linkage on the starboard eng either came loose or broke during all the docking attempts..
                        The inverter came on by itself late Saturday and worked great we thought until we disconnected from shore power Sunday to go out. I had to switch from bank to the port Battery to keep the chart plotter working. the autopilot worked for awhile and then gave a ECU (I think) failure so I turn it off.
                        We are still playing it safe on heading out it was supposed to be 2 to 3 but the winds kicked up and the interval shortened so we just stayed in the bay.
                        I have a mechanic that has come highly recommend and he specializes electrical. so hopefully we can sort out the issues..
                        thanks again to all for your input and SUPPORT of the new kids

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                          #29
                          Continues to be a great thread....I read on this thread that a good general rule is 1 foot wave per 10 foot of boat. Sounds much more accurate than the statements I've read about 20+ foot bowriders being good for 3' waves.

                          I've been caught in 3 footers in a closed bow 20' Sea Ray and didnt drown, but that's about all I can say good about the experience. Choice was waves over bow or waves over side...most of yall have much bigger cruisers but it's all relative I reckon.
                          2008 H210SS Four Winns
                          Volvo Penta 5.7 GISX
                          Prior: 1997 2050SS Bayliner
                          Brad / Texas Gulf Coast

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                          • Centerline2
                            Centerline2 commented
                            Editing a comment
                            3 foot wave can be dangerous for large cruisers also, but as you said, its all "relative" ....relative to the frequency of the waves and the experience of the skipper.

                          #30
                          I sure agree there is not one specific go-no go pin to pull. The totality of the WHT, DPD, WIND, CURRENT, TIDE, ETC, must be analyzed. Heck last summer at Catalina I had my 10’ dinghy out fishing in 6-7’ swells but the DPD was around 15 secs. with no wind. It was actually fun to ride em up and down as the faces were very shallow.
                          Jim Gandee
                          1989 3888
                          Hino 175's
                          Fire Escape
                          [email protected]

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