DE23 / OP21(3) Questions

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tobi
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DE23 / OP21(3) Questions

Post by tobi »

Dear Forum

I am thinking about building a boat about 23 feet long with a raised deck in front. It will be mostly used for weekend cruising with a family of four people in inland waters and the wadden-sea in Germany, the Netherlands and in the Baltic sea. As we plan to sleep on the boat, the head has to be separate to be used in the night time without waking other sleepers. To get this, there will be a V-berth in the front of the cabin, followed by a head with just sitting headroom on one side and a small kitchen on the other side. The cockpit will be open (like in the OP21) and can be closed with a tent to sleep two persons on inflatable mattresses. The boat will be on the trailer most times, the trailer weight should be below 1.100 kg or 2.420 lbs and the beam should not be more than 2.55 m. I would like to build a teak deck with thin teak on plywood in the cockpit and above the cabin.

Two different hull seem to be possible.
1. The DE23 seems to fit.
2. A stretches OP21 might be an alternative. It will be a little bit complicated to scale (first shrink in all dimensions to reduce the beam, than stretch the length), but it seems possible to me.

8144
DE23 raised deck

8146
OP23 raised deck

A big difference between both boats is the way the cabin is build. The boat based on the DE23 would get one partial side panel that forms the side of the cabin. The the boat based on the OP21 would be different, the enlarged side panel would reach to the deck.

My question is which hull form is better suited for the intended area. The inland waters mostly have speed limits between 4 to 8 mph. On the flowing rivers I would like a faster boat like 20 to 25 mph, especially when running against the current. The waves on the rivers and the coastal areas when using the boat will not be higher than 2 feet, but they will be steep an often with chaotic directions.

Which plans should I buy? Any advice is welcome!
tobi

rick berrey
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Re: DE23 / OP21(3) Questions

Post by rick berrey »

I don't know if you have looked at the FL26 , material and weight will be about the same as the DE23 , maybe less , beam 2" narrower , 2' more deck space , already laid out like you want . Look at the pictures in the gallery of the FL26 with the soft top .

fallguy1000
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Re: DE23 / OP21(3) Questions

Post by fallguy1000 »

de23 suits you better; lotsa builders; just put 70hp on it and it'll handle anything, current or waves
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tobi
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Re: DE23 / OP21(3) Questions

Post by tobi »

There are some very nice boats with 26 feet length. The FL26 looks nice, the bagatelle from hylan with a covered outboard has a really nice concept to me.
But they are 3 feet longer. As the boat will live on the trailer most of the time it is important to keep it as small as possible.
It is of course a compromise. With unlimited length I would build a covered outboard like the Nina to reduce engine noise and for the looks (like the DE29 build in the Netherlands). But this would result in a bigger boat > bigger trailer > bigger car and building space.
So it is the complicated decision about keeping it small for ease to move an the road and in the water opposed by the demands of room, the look and luxury like sound isolated engine.
For me the result is more 23 feet long.

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Re: DE23 / OP21(3) Questions

Post by rick berrey »

Trailer length for a FL26' would be longer but the weight of a DE23 -v- FL26 is about the same . Beam for the FL26 can be brought down to 7'9" which would be a + in Europe . There is a picture of a nice Nina in the Gallery with a cabin , I think you would have to scale up a Nina to get close to what you want , not sure it could be done .

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Re: DE23 / OP21(3) Questions

Post by TomTom »

Tobi if your intention is to go fast/ faster when you can then this narrows your search down already. You stated a top speed of 25 mph - which rules out the FL 26 - although it is a good candidate in most other aspects.

You also don’t mention how much you care about engine size/ efficiency.

I tend to agree with Fallguy that the DE23 will suit your needs within the 0-25 mph category better than the OP21 - and will do so on lower power.

You could put a bracket in both designs - which gives you a longer cockpit space - and makes the boat quieter - which you said somewhere was important.

As far as the layout of the cabin goes, within reason you can pretty much do what you want, so long as you don’t make it too heavy and you keep the structural frames - so how easy a plan is to modify to your cabin layout would be the lowest thing on my priority list.

Pick the hull that suits your intended use first.

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Re: DE23 / OP21(3) Questions

Post by rick berrey »

Another option if adding length would be to go with the DE25 cabin version , your layout would fit , it is only a sheet or two more ply , very little more weight considering you are only covering the cabin anyway .

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Re: DE23 / OP21(3) Questions

Post by TomW1 »

I feel the DE23 would be an excellent build for you. With one of the new 70HP motors from Yamaha or Mercury you would be able to handle both your speeds you need at an economical rate. It sounds like you only need the 20-25 mph for shorter periods of time. I ran the DE23 at 2600lbs through my calculators and with the 70HP your top speed will be in the very low 30mphs, say 31-33. So at 20mph you will be at about 3000-3500rpm's but only real world testing will tell.

I looked up 3 trailer builders and if you stick to an aluminum trailer your trailer weight will be around 1800-2100lbs. So no problem there. These were all dual axle trailers capable of holding 4-7000lbs. Much more the a DE23 will weigh. You will just have to shop your trailer builders over there to find one that you feel is right for the DE23. If you are going to keep ii on the trailer go with bunks not rollers and make sure they are under the stringers.

As far as moving the bathroom is concerned once the sole is down, you can move things around any where you want. Put the head aft of the sleeping area and move the eating area aft, or move the cooking area aft. It is really up to you. Leave the V-bunks in place and start drawing how you want everything else you want behind them. That is the fun of building your own boat. :D

Well take care and good luck on your decision. The above is my opinion.

Tom
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Re: DE23 / OP21(3) Questions

Post by BarraMan »

I am admittedly pretty ignorant in the boat design area - but I really struggle with the concept of that boat doing 30 mph (25 kts) on 70 hp! :doh:

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Re: DE23 / OP21(3) Questions

Post by fallguy1000 »

BarraMan wrote: Mon Feb 01, 2021 2:42 am I am admittedly pretty ignorant in the boat design area - but I really struggle with the concept of that boat doing 30 mph (25 kts) on 70 hp! :doh:
Depends on loading; weight of superstructure.
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