Seaway Conversion

I had a little time to shorten the 5:1 this weekend. This was my take on it. I'm not exactly sure if this is the correct reeving but it seemed like every other way caused the main to cross. There are a couple things I did differently than what I've seen on other versions. 1. the becket was added to the double block 2. I made a small swivel piece for the double block(I contemplated using the sprung swivel that connects the ratchet block to the double.) 3. I eliminated the sprung swivel from the triple using some thick washers.

The finished product:


The triple: Here you can see the outer bolts get a double thickness washer. What cannot be seen is the inner gets a standard thickness(1/16?) washer. The ratchet adjustment bracket gets a 10-24 washer. Also the set screw that is inserted is cut down so that it doesn't protrude into the sheave sidewall. If you tighten your center bolt and your ratchet sheave starts to catch when it rotates it will catch every 120 degrees of rotation which is where the cast centering pins on the sheave are located and your set screws are too long.



The swivel and double: The swivel is lighter and simpler that using the sprung swivel. I was going to cut the plates down to about 9/16" and cut a center hole through which the pin on the double could pass through but abandoned that idea and made the little bracket. If I were to go a step further I'd cut the main swivel pin shorter and drill a new hole for the shackle pin. The double has enough play in the swivel pin assembly to accommodate a plate in the middle so the becket plates can be used as well as one of the end plates from the double.

This has always been a great way to update older boats for very cheep, but if you have access to 1 extra block you can make it into a 6:1 like modern boats. The brackets for the tie point need to be bottom center but having 3 blocks up top avoid the issue of the centering bracket for attaching to the boom.

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Catamaran Racing Association of Michigan - Marketing Officer
USF18 - Social Media Manager

2010 NACRA Infusion
2004 F18 Hobie Tiger - SOLD
Hobie 16 - BREAKPOINT - SOLD

Yup just getting a third single make the whole latter part of the work unncessary since the swivel pin is centered on the middle block. I've got one on the way off ebay and I already purchased the bolts for it. I'm going to sail it this way for I while so at least I know what the difference feels like in my hand. All I need is a pad eye so it can be terminated on the opposite side of the cam cleat. I got my single off ebay for less than 20 shipped. Going this route will total out to the following at least based on the prices for stainless at my local hardware store

3.5" bolts 6x $0.65 =$3.90
nylock nuts 6x $0.25= $1.50
1/4" Washers 6x $0.08= $0.48
Seaway singleblock 10-20$
Pad Eye $3.00

So if you have a working factory main you can convert it to a 6:1 for as little as 20.00.

On the top double, maybe eliminate the becket, and tie sheet to 2nd (aft) attach point (where single used to hang).
Might allow for sheeting tighter.….
What you think?

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'84 H16 #80116 Tequila Sunrise

If you affix it to the boom pad eye it will no longer rotate with the block set is the only reason I can think of. It's definitely simpler and cuts out the length of the becket and knot. I'm taking it out today and we'll see how it works. My boat is an 83 so I'm not even sure I can get enough rake out of my mast to get it to bind.

Let us know how it works!
My 84 needs more rake, interested in how your rigging does.

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'84 H16 #80116 Tequila Sunrise

What size/model number/make block did you buy on ebay?
I'd like to do same, need to know what block to get...

Also, your shrouds and adjusters.....stock original or newer shorter shrouds and longer forestay maybe?

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'84 H16 #80116 Tequila Sunrise

I too have thought about doing this, I found the instructions at one time but I can't remember where they were. If you have the time, could you describe every step in doing this modification, I really don't want to screw it up. Lol.

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Marty
1984 H16 Yellow Nationals Redline, "Yellow Fever"
Lake Martin, 'Bama.

Here you go

https://www.hobie.com/forums/viewtopic.php?t=37024

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84 14T Redline #67 Blue Hawaii faded but still working!
82 Yellow hull16 '81 Boomer nationals 20.9 on GPS
83 White hull 16 No sails "Clean and Purty Now!"
87 White hull no sails no tramp

Hey all just an update. I took it out last night. It was glass when we were rigging but by the end of the evening we were flying the hull briefly. The conversion worked flawlessly. I couldn't get it block to block since I have the older shroud lengths however I could get it shorter than would be possible if I had the older setup. This is my third time out so I'm getting a feel for it and I can definitely see why people opt to go 6:1. If I hadn't been naughty and cleated the mainsheet and i was sailing under windier conditions my hand would have been so tired of keeping on the tension. I'd gladly trade the response for that purchase.



I just searched for used Hobie parts and the keyword block or pulley. I saw a couple on there when I got mine.

https://www.ebay.com/itm/Vintage-SeaWay ... ition=3000

Just started my 6:1 conversion today. I was able to pick up a single Seaway on Ebay a week ago. I also ordered some 8mm Salsa line to go with it, as well as a Harken 150 cam cleat to replace the stock Seaway one.

The seller I purchased from still has some, take a look...
https://www.ebay.com/itm/Vintage-SeaWay ... Sw~xVbcQWW
https://www.ebay.com/itm/Vintage-SeaWay ... SwE0JbcQXj

I'll throw some pictures and details on my conversion as I get it finished. Hopefully I will find time this weekend. I'm going for the 6:1, becket removed from the center pulley of the top triple, and a pad eye installed opposite of the cam cleat for the line tie off. I have a harken 150 on the way to replace the oem cam cleat, should work a little smoother and not tear up the line as much. A simple adaptor plate will be required, I will also show how I did that if anyone wants to upgrade the cleat.

Cool, thanks.

Sent from my SM-G955U using Tapatalk

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Marty
1984 H16 Yellow Nationals Redline, "Yellow Fever"
Lake Martin, 'Bama.

I wonder if this would work for a top triple block to get a 6:1.

https://www.westmarine.com/buy/lewmar-- ... ecordNum=4

Price isn't bad if it would work.

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84 14T Redline #67 Blue Hawaii faded but still working!
82 Yellow hull16 '81 Boomer nationals 20.9 on GPS
83 White hull 16 No sails "Clean and Purty Now!"
87 White hull no sails no tramp

Question on conversion triple for top block...
With 3 blocks bolted into a triple, would it be ok to hang from center block only, or would I need a triple bracket to spread load?

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'84 H16 #80116 Tequila Sunrise