Info on 1978 21' Hewes Marlin Construction

Discussion in 'Powerboats' started by NavYak, May 27, 2016.

  1. NavYak
    Joined: May 2016
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    Location: Kennesaw, Ga.

    NavYak Junior Member

    I have recently acquired this boat and have had no luck finding any info about this Boat. Wondering about max power and if i can go offshore with her without any problems. I am going to have to replace the transom but everything else seems to be in good shape.
     

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  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Welcome to the forum.

    Like many companies from the 70's, it was likely bought up be someone.

    Have you checked her stringers? Are the soles soft? Going offshore is more skipper skill than boat, though the boat can have a huge impact, on your comfort level and it's ability to take on the bigger seas, found there. The pictures don't show enough of the hull to get a real good idea of how suitable the shapes may be, for serious offshore work. How much deadrise does it have? What's the max width of the transom and how is it powered?
     
  3. NavYak
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    NavYak Junior Member

    right now it is powered by a johnson 115. i am thinking of going to a 150.
    max width at the transom is 7'. not sure of deadrise, think it is around 15 deg.
    here are a few more pics.
     

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  4. NavYak
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    NavYak Junior Member

    About the stringers and the deck, i had someone look at it and they said it is just fine. part of the transom is starting to rot so i am going to replace it. Mostly i wanted to know how far offshore i could go to fish. if i can't go far in this boat it is just fine. just want to have fun and fish.
     
  5. PAR
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    PAR Yacht Designer/Builder

    That doesn't look to be 15 degrees, more like 12 and this wouldn't be typical of an "offshore" boat, but again if used wisely, you'll be fine. When it gets rough out, the ride will be fairly harsh, but it could be worse.

    Who looked at it and what do they know about checking stringers? Most folks don't know their stringers are bad until the soles go soft. My point is, that era of that boat suggests if the transom is going, so are the rest of the internal support structure (stringers, beds, partitions, etc.) and an inspection requires some skill, not guess work, particularly if heading offshore.

    Your boat should be able to handle slightly more than 200 HP, though check the transom thickness, which is a good indication what the manufacture expected from her. It should be in the 2 1/4" to 2 3/4" range for this kind to HP.
     
  6. Mr Efficiency
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    Mr Efficiency Senior Member

    yes, it is quite a moderate vee aft, which is good for fishing out of though. It looks a little like a boat a friend had once, that I went out with him just the one time, which frightened me with broaching tendencies ! But maybe I am being unduly pessimistic. It is notable that there is little sign of a flat at the chine, which might explain why it has tabs fitted. I'd reckon 150 hp would be quite adequate, unless the boat is unusually heavy.
     
  7. NavYak
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    NavYak Junior Member

    SO i guess this boat will be more of an inshore fishing boat. which will be fine also. The transom is 2&1/4" thick.
    It was a local boat repair guy that said there wasn't any soft spots nor moisture present in the stringers. Don't know the people here. haven't been here long. moved here to be closer to family after i retired from the Navy. But i will probably move back to Florida to be closer to the ocean.

    I don't believe the boat is heavy, i pulled it with a 2000 Jeep Grand Cherokee with a 4.0L Eng. seemed to pull without any problems.
     
  8. NavYak
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    NavYak Junior Member

    I was also told that the 115 held its own well fishing inshore on the east coast and west coast of Florida.

    I will probably pull the floor even tho i know the floor was redone in 2000. The boat belonged to my father in law and he took very good care of her, and always kept her under cover in 1 way or another.

    I have been tossing around the idea of doing a full restore. I Have experience with composite construction and repair working in aviation maintenance. so i am hoping that i can transfer my knowledge to marine maintenance as well. Hopefully i can find people who will be willing to show and work with me so i may learn a few things.
     
  9. NavYak
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    NavYak Junior Member

    Thank you PAR and Mr Efficiency for your comments and insight.
     
  10. Mr Efficiency
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    Mr Efficiency Senior Member

    If the sole (floor) has been done and feels solid, don't rip it up, imo. I'd cut a couple of circular holes that you can later install flush inspection ports in, and prod around a bit with a screwdriver along the stringers, to check them. Don't cut into the fuel tank, though ! You can also use ports to install buoyancy, for some extra re-assurance, if there is room in there. That is another subject though, to do properly you really need it away from the centre of the boat, and higher up.
     
  11. PAR
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    PAR Yacht Designer/Builder

    Pulling a boat with a car doesn't really tell you much. It needs to be weighed, which is easy enough. Weigh the boat and trailer at a truck scale, then go launch the boat and weigh the empty rig again. Another method, which you can do in your driveway is to place a scale under the trailer jack and note the weight. Next, move the boat back on the trailer and weigh the rig again. Next, get the axle to jack distance and divide by the distance the boat moved in inches.

    If the sole (what you're calling the floor) was already done, I find it hard to think they'd have left bad stringers in place. Simply put, you're probably okay on the stringers and soles. I agree in the access holes, which can be closed up with deck plates. They permit the bilge to vent off condensation, offer some storage and/or a place to install floatation if desired.

    Most of the builds from this era didn't provide adequate weeps and limber holes in the blow sole structures, which causes moisture to collect and rot stuff out.

    If you make down to sunny Florida, look me up.
     
  12. NavYak
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    NavYak Junior Member

    Thanks again for all the Advice. I had already planned on weighing the trailer with and without the boat so i can know what it actually weighs. I wish i could find more specs on the boat from the manufacturer. I already did an HIN search, but that only produced info i already had.
    I will definitely cut access holes. That is something that i am familiar with utilizing in aircraft as well.
     
  13. NavYak
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    NavYak Junior Member

    By the way the fuel tanks are on each side of the boat. Not sure if this is optimum, or if i should remove them and install one below the deck.
     

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  14. Mr Efficiency
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    Mr Efficiency Senior Member

    As PAR says, you need a weighbridge for accuracy. Fuel tanks on the side like that isn't ideal, raises centre of gravity,and you have to be wary of uneven draining. And there is something else to kick your toes on ! The tanks are too close to the stern too, by the look of it.
     

  15. NavYak
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    NavYak Junior Member

    I will remove those tanks. I have a spare 26 gal. fuel cell that I can install. I just have to find the right spot for it.
     
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