Alan Stewart

Epoxy always needed on everything everywhere. That's the best method. The epoxy is a barrier to moisture. Moisture makes wood shrink and swell. Shrinking and swelling causes cracks. Cracks let in more moisture. Full epoxy encapsulation of all wood is the best most long lived way. Okoume plywood is not very rot resistant at all. If it's wet it will rot in a couple seasons. The Gougeon Brothers built the adagio Trimaran in 1969 and she's still going strong. All epoxy and plywood bonded and i'm sure every bit is coated in epoxy.

I wouldn't bother if it's going to get 10oz over it later but I am a fan of putting down 4oz on something if i need to finish it quickly but you still usually need a "fill coat" on top of the glass if you want it smooth. If you put too much epoxy then the glass just floats and you still get the weave. I find the best is to do a heavy coat on the bare wood and put the 4oz glass down and let it soak up the epoxy and let that set up then a few hours later come back and coat that again as a fill coat. OR use peel ply over the 4oz then it's a 1 step and done. It is heavier than 3 coats though. If the parts are flat on the table though you can just do a heavy flood coat but it's hard to know how much there is and easy to use a LOT. Sand the ply smooth with 220 before you coat if you want to try to do a one step flood coat for best finish else you could still get some wood grain/fuzz rough texture on it.

Planning to store the boat in the garage so that solves that. Big Garage = fewer problems

I'm trying to get INTO the shop more. Normalize on board 3d printers!

Thanks Steve, I'm feeling motivated and have been enjoying doing lots of "add to cart" activities. Keeping the pressure on and doing lots of small tasks each day. I need to be painting the cockpit in about a week and half so.... Tabernacles glassed, mast tube collars made, Rudder cheeks glued on, cabin shelves assembled with superglue then coated. I also have my dodger materials on the way and i even cut out a windvane rudder. The idea being to work on everything all at once so if I'm waiting for glue to dry I can just pick up another thing and work on that. Taylor is going to sew up our bunk cushions. The only question is where am i going to sleep? Probably end up in the cockpit. I'm not going to do nonskid additive and instead am going all in on foam decking. I've bought 3 pieces of this EVA foam diamond pattern foam same that i used on my plywood foil board and am planning to put that all over the cockpit seat tops, hatch tops maybe even some on the cabin top and cockpit sole. https://amzn.to/4art0uH Anchor and anchor roller are on the way and i've got most of my electrical stuff already. I bought an Ecoworthy 12v 280Ah battery which fits just about perfectly in the battery box too for power and about the cheapest per kwh for LiFeP04 you can get right now with good quality I think. https://amzn.to/4aYiYkU. I was happy to see this battery still makes Will Prouse's list recently. That gives 3.5kw of power to run whatever. Planning to experiment with a trolling motor, can run my starlink mini maybe an on board 3d printer. Still some room for a bigger battery but that'll do! Dodger hardware

Well, it's finally happening. Started the boat in 2016. Then we converted over to the taller 2018 version. Worked hard on it for 2 years and even launched the boat briefly at the 2020 messabout and slept aboard at the dock. Then I thought it was happening in 2024 https://bandbyachtdesigns.substack.com/p/raising-boys-and-boats-its-finally but the boat turned into a table again. (funny how fast that happens). So 10 years it is. Henry is 5 now and heading off to kindergarten in August. James is 3 and we're all going to Raid Erie event at the end of the July. That was the catalyst for finally finishing our Core Sound 20 Mark 3. Below, the boys helping vacuum out the cabin. So using proper boatbuilding technique I've waited until just a few weeks before to finish it. Photo album is here which I've started adding to again. https://photos.app.goo.gl/22Tfg2WR5pTSBHyw1 On the list.... Glue down cockpit sole Install Tabernacles Build masts Build Centerboard Build Rudder Paint Hull, deck, cockpit and cabin Rig the boat Sail the boat Put boat on a new trailer. Maybe get dodger built Maybe pull a wind vane out of a hat I copied what i did on Graham's rebuilt 17mk3 rudder and installed integral pex tubing for the up and downhaul in the rudder cheeks which worked well. Tabernacles are assembled and ready for glass.

I would definitely want trim tabs. The doel fin on the outboard I thought was more of a band aid fix for boats that ended up with too big a motor on the stern and wouldn't plane out at lower speeds without it. I don't think the Marissa would need one even without trim tabs and they add drag/reduce fuel economy. The purpose of trim tabs is to adjust the ride angle to maximize performance at a given rpm and to adjust how the boat behaves in a chop like being able to put the bot down into a short chop to smooth out the ride. Also in a crosswind to level the boat out. The hull is already nice and light so adding a foot of length and 4" of beam at the chine will make her float even higher. I'd probably just leave the chine beam alone if you want to widen the boat just do it at the sheer and gain a bit of cockpit width, i don't think the boat needs more beam really. Wide chine flats have been tried and I don't think there is much benefit plus the slapping is def probable. All the custom 25, 30 and even 52 footers have about 2 1/2" wide chine flats with sharp edges for spray.

I know Graham was thinking of doing it. I'll be feverishly trying to finish my 20mk3 for the Raid Erie event and I just toured Core Sound the other week so maybe next time for me.

That's essentially correct. It also has the ability to passively fill with a valve you open or shut reaching through the tank hatch. That's the red x. Also valves in the locker so you can isolate the tank from locker if a hose fails. All water enters and exits the tank via the trunk hole. https://photos.app.goo.gl/ov83K1tS2iHf2pEQ9 Im gonna do something similar but utilizing my outboard well in the cockpit i think.

Eric posted this a while back on the fb group.... I presume that's the campground on the island. Im planning to leave my car at the East harbor state park campground and sail over. I think there is a group doing that then stay on the boat. The St. Hazards website is only set up to handle reservations for 10 tent camp sites, but the campground has room for many, many more tent campers. They will basically never run out of room. When it shows full, it just means you can't reserve using the website, you need to call or email to reserve: email: info@sthazards.com, phone: 419.285.6121 or 419.307.6214 I recommend calling, leaving a vm, and texting both numbers since its out of season for them. Do not worry! you can even show up to St. Hazards during our event with no reservation at all, and they will accommodate you! Promise!

Its just copied from a fb post on the raid erie fb page. https://www.facebook.com/share/p/1FAwkWtXUj/

I told my parents they should take their boat to Raid Erie but then we got to thinking hey we could actually do it too. So we're registered! so now I MUST finish my 20mk3 and they're going too. And I see already Erik is going in his 20mk3 also Niels Wade with his P22 and Andrew in his CS-20. Here is the participants list form March 10 posted by Eric Miller the organizer. Paul was there last year.

A cool video of MadMothist Leaving Flamingo using the pedal drive. hard to tell how much work the sails are doing but obviously the pedal drive is assisting well though that channel is very narrow so he ran aground. Love the huge bowsprit too. Tom has this cool longer video too from around Flamingo...

Hey Jonathan, Yes we'll have kits and plans very soon. just have to get a couple of pesky powerboat jobs off my plate then i'm all over it. How much space do you have. Send me some pictures and measurements so i can check in the 3d model what if anything you'll need to do space wise. it'll probably fit. I like Andy the autopilot and Walter the windvane. My Dad had fun with Phil and Dwane the brothers that control the ballast tank.

In case anyone isn't subscribed to the newsletter. here is a link to our trip write up. https://open.substack.com/pub/bandbyachtdesigns/p/dawn-patrol-2-an-ec-debut?r=2cxnpo&utm_campaign=post&utm_medium=web&showWelcomeOnShare=true

The definition of "cool...but". Someone was like make it do this and some engineer probably spent a week designing it so it would work and not be as good as a simple lift out. Don't drop anything down that crack. hahaha

Well weve been doing it every year just not always a trip report. But last 2 years weve been in the 17mk3. yes the windvane is quite happy to steer in any wind above about 3 or 4 knots of apparent wind no problem. So far we've probably hand steered less than 10% of the time.

We are tired of rowing. We wouldn't row just because there isn't wind unless we were really racing hard. We're trying to use our brains more than our muscle this go around. Sleep more think harder.

Haha. This year we didn't bring a spinnaker or oars. We were up to the wire getting the boat done and wisely I think prioritized the windvane getting done. So far we wouldn't have used a spinnaker much def not required. We thought oars for this boat would be too ungainly since the coaming is so high bet we are rethinking that. The mirage drive off the transom really didn't impress. We didn't even bring it. Our only mode of aux propulsion is 2 stand up paddles which works quite well especially if you do it from the low side the coaming is narrow and its easy to do a normal stroke and the heel brings the wayer closer to you.

In case you're not on our newsletter, here is a link to the info on our race. Much to my Dad's chagrin I thought it would be super cool to livestreaam our race from the boat so we're going to give that a go! Wish us luck! https://bandbyachtdesigns.substack.com/p/everglades-challenge-2026-live

Didn't mean to confuse. When i said i raise the main at the dock that would be after raising the mizzen. In other words I usually always raise both sails at the dock and then sail away and if my main is going up my mizzen is already up. Mizzen up first always. I never have my main up without the mizzen up. You're depowering order is exactly correct with the slight sidebar that.... The ballast tank should always be filled when sailing the 17 or 20mk3 UNLESS you have the mast head float (which I know you do) which makes it an option to sail sans ballast. Or to put another way, I'd say that the 17 and 20 mk3 were always designed to be sailed with ballast since you can't effectively "hike out" (and you're not meant to) and the decision to make that ballast water ballast was in order to make the boat lighter for trailering and launching/retrieving. You can absolutely sail with just the reefed mizzen we've done it lots. Works great on a reach or any downwind point of sail. In a pinch it works upwind too in strong winds but you have to carefully mange the weather helm and keep the boat speed up and it likely won't work in very choppy conditions. https://smallcraftadvisor.substack.com/p/double-enders-vs-transom-sterns Below a picture I took from the North Carolina Challenge. Great conditions for 2 finger sailing down long wind swells with double reefed mizzen.

I usually raise the mainsail at the dock and then sail away from it. If you don't like doing than then I presume you motor or row away from the dock first (which is fine) and in that case you raise the mizzen all the way first which allows you to heave to on one tack and then raise the main. Unless it's absolutely honking conditions that should be no drama so long as the main doesn't get caught on something and pull the bow off. The way i'd do it would be not to heave to completely but once the boat was moving under mizzen alone on say a reach, i'd head up into the wind slightly and sheet in the mizzen close hauled and lock the tiller off straight ahead. Then move forward and pull the main halyard. If you're sufficiently head to wind (but not too much so you don't go into irons) it should shoot up easily as long as you don't have the downhaul cleated, snotter too tight or mainsheet sheeted in. Once it hits the top of the mast, a tug on the snotter tension and main downhaul and you're done. Maybe takes some practice but that's it. Should be done before the boat loses forward speed so you can sit back down, ease the mizzen sheet, bear away slightly, sheet main in slightly and you're sailing away.

Some good info there in past threads. I've added my 2 or 3 cents below. The best thing to do is take your boat out and try stuff. Be prepared to realize that the procedure is different depending on the conditions. A handheld GPS is super handy for see what works best for heaving to and not losing ground. The gustier the conditions the harder it is to keep the boat parked and stable. In all cases the main sheet MUST be completely free and loose and in all cases you have to decide which "tack" you want to heave to on. Port (wind coming over the port side) or Starboard. Pointing directly into the wind isn't heaving to. If you sheet the mizzen in, let the main out and then just let go of the rudder your likely to have the rudder swing violently over to one side as the boat chooses the tack your going to be on for you and begins drifting backwards. You can damage the rudder doing this especially if you don't have rudder stops. It's essential to have a way of locking the tiller (rudder angle) in order to heave to effectively in all conditions. I usually raise the CB when heaving to but it depends on conditions. Raising the CB allows the boat to slip sideways which is a good thing when heaving to. You don't want the boat to get going. you want it to drift slowly perpendicular to the wind or drifting slightly downwind on one tack or the other. Light wind easy sailing flat water 8-12 knots. Round up and sheet in the mizzen all the way (not crazy tight but fully sheeted). Then decide which tack you want to be on and let the main sheet out and give the sheet some slack (pull some slack out for it). Head up into the wind and let the boat speed drop to zero. Once boat speed is zero you can push the rudder over to the "lee" side. About 20 deg or so but not on center. If you just lock the rudder on center then you'll start drifting backward very fast 2 or 3 knots just from the wind pushing the boat backward. You don't want to lose ground that fast or have that much flow over the rudder backward so rudder always needs to be off center. You'll be drifting backwards very slowly or not at all if you do if correctly. The boat will "hunt" about 10 deg or so up and then down. As it falls off and the mizzen catches some wind the boat will get a little energy and squirt forward and as soon as it does and there is some flow over the rudder, the boat will head up just a bit and the mizzen will luff allowing windage to take over again and the boat will slow, stop, and fall off again. Cycle Repeats. If you want it to be a bit easier drop the mainsail all together and reduce some windage on the bow. Reefing while Heaved to This is how you "stop" the boat to put in the first main reef. When you do however you MUST NOT pull the mainsail "in" or you'll bear away and start sailing. You have to recognize this instantly and let it go or better yet you can control the boat by holding the main sail. Push it away from you to bring the bow back into the wind, pull it in to prevent the boat from tacking and knocking you overboard. If you have the reef lines led aft like the 20mk3 then you can do the reef without influencing the main sheet angle at all. Higher or very gusty wind. I've found that in higher wind or very gusty wind that can quicky switch directions by 10-20 deg. It's better to let the mizzen out just a bit (not sheeted all the way in) so that the boat parks at angle further "off the wind" say about 30-40 deg off the wind. Especially if you haven't reefed the mizzen. I also lock the rudder further off center. Having the rudder further off center makes that boat react sooner to a gust that hits the mizzen and having the boat sit slightly further off the wind makes it more resistant to a gust coming in from a different direction. If you have the sheet in tight and rudder just slightly over that boat will sit perhaps only 20 deg off the wind and a gust can cause the boat to tack. If the boat tacks you've got to change the rudder to the other side. In higher winds and chop if someone is "going forward" to reef the main then the helmsman should be careful to keep the boat just off the wind and stable for the crew. If alone, you've got to keep an eye on the boat's state when you go forward and touch the mainsail so as not to cause the boat to bear off or tack and push you over the side if you're caught unaware. You can never have too much situational awareness on a small boat! In very rough conditions it may be easier to reef the main by dropping it entirely and then doing what you need to do rather than standing on the foredeck if you don't have the main reef lines lead aft. Raising the rudder? If you don't care about drifting backwards at all then let the main out, mizzen in and just lift the CB and rudder out of the water. In light wind the fastest you'll drift is the wind speed directly downwind and you don't have to worry about being on one tack or the other. I rarely do this because I think you can just as easily park the boat and not lose ground by keeping the boat plodding along as described above with rudder just off center.

Nanocruising, a small podcast in Canada contacted us about doing an interview about the Core Sound 17. Graham shares some history and insight into the design. Good job Graham! https://www.nanocruising.com/

In the plans the trunk is show in full size sheets so you're right the trunk slot width isn't mentioned directly but it looks like it's 12 3/8" inside. Feel free to make the dagger a closer fit if you like, you're right that it won't make a noticeable difference sailing but Some fore and aft play doesn't hurt anything.