1988 205 Sundowner-What is this thing under my swim deck?

jbrfun1

Cadet
Joined
May 3, 2003
Messages
6
Hey Everbody,
I have a very nice 1988 Sundowner 205- 4.3 ltr chev with cobra outdrive.
Underneath the aft swim platform is a big (approx 1 ft diamete)r white plastic disc with a screw off manhole cover that has an O-ring seal in it. When you open it up, all I see is the substrate of the swim platform and the glas coating underneath it. What is this thing and how should I be using it ...if at all? Am I suppose to open that up to keep back transom area dry after use? I don't get it.
Thanks for any and all responses
Jim
 

John880

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Oct 22, 2009
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Re: 1988 205 Sundowner-What is this thing under my swim deck?

Jim
I'm not familiar with your model but I have a Vista 278 with a swim platform which is essentially part of the hull. To install or remove the stainless railing or the dinghy davits I have to fit in to a very small place in the engine bay and struggle to reach the nuts and washers from the inside. I am very envious of owners who have a hatch to facilitate access and have often considered installing one. I suspect yours was installed for easy access for a fitting or two or to facilitate a repair job to the fibreglass. Shortly after buying our boat I removed a railing from the swim platform for a repair that involved welding. It was suggested that I cut my way in and repair the fibreglass or install a hatch but I did it the hard way. In a situation where a swim platform is bolted to a hull then access would be required for initial fitting and subsequent removal.
John
 

DBreskin

Senior Chief Petty Officer
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Oct 20, 2009
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Re: 1988 205 Sundowner-What is this thing under my swim deck?

Pictures may help us to figure out what it is.
 

jbrfun1

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May 3, 2003
Messages
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Re: 1988 205 Sundowner-What is this thing under my swim deck?

Thanks for the response guys..I'm not sure how to attach a pic..but I'll try...And have a nice Summer in Perth, John! We're headed for snow here!
Jim
 

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John880

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Oct 22, 2009
Messages
19
Re: 1988 205 Sundowner-What is this thing under my swim deck?

Jim
Your hatch appears to be directly below the boarding ladder - does it have something to do with access to the bolts securing the ladder? Looks like it will be very handy if the ladder ever has to be replaced or repaired so glassing over the hole would not be a good plan.
We use our boat year round in Perth but I will not get too smug about it because we have also lived in Canada and I have shovelled my share of snow.
John
 

jbrfun1

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May 3, 2003
Messages
6
Re: 1988 205 Sundowner-What is this thing under my swim deck?

Thanks for the response, John. You could be right, I suppose. If you had to get a wrench on the nuts, you could probably do it from there. MY concern was that it was an intergral piece that I should concern myself with. As long as it doesn't appear to be a stock item on the boat...that solution works for me. Thanks.
Jim
 

John880

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Oct 22, 2009
Messages
19
Re: 1988 205 Sundowner-What is this thing under my swim deck?

I am now wondering if a plastic hatch is strong enough to be used under water. If it was mine I might consider taking it off and using it as a pattern to cut and drill a stainless steel cover which could be sealed with Sikaflex or similar. I once had a reputable brand of aluminum boat which had a plastic hatch on top of the swim platform. Mine started to crack up, another local owner took in water from his - the factory had recognized the problem and gave me a replacment plate in aluminium. Our problems probably arose from the hatches being walked on which is not going to happen to yours but it could get slammed in heavy seas.
John
 

jbrfun1

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May 3, 2003
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Re: 1988 205 Sundowner-What is this thing under my swim deck?

Thanks for the input....I'm actually not too worried about it breaking, although the seal looks kind fo funky and I will probably remove it and reseal. It is a substantial piece, it looks like at least. This is freashwater country here, with little or no chop to handle, unless I take it out on Lake Michigan...in which case, it could take a slapping. But, that's only 57 F degree water temp, so no worries, right? I've got twelve minutes in the water before that leak won't matter and i pull a DeCaprio.
Although, I will guarantee you that when i pull it off to reseal, if it looks suspect, then a lightweight stainless disc is going in it's place...thanks.

Jim
 

Lou C

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Nov 10, 2002
Messages
11,802
Re: 1988 205 Sundowner-What is this thing under my swim deck?

That's definitely not original to the boat, and I'd think about taking it off and coming up with something more watertight. Right above that is a gap inbetween the lower and upper hull halves, and if water got it, it would start rotting the wood in the underside of that swim platform area. I think the OE ladder probably fell apart, or had to be replaced, and the replacement ones had to be attached differently or with a different bolt pattern. You can access those attachment points, but it is very difficult, in the gap between the upper cap and lower hull. My 88 Horizon has the same lower hull, different upper cap.
 
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