Scorpion Hull experts ? Help needed please!

[1978SeaRider]

Hi,

I've had a bit of a nightmare with my Scorpion and I'd be very grateful of any advice / help please.

Basically, after my cover and bilges failed over winter she filled with water (fresh). She's back on the water and we even did a trip from Holyhead to Dublin last month - so she's mechanically sound.

However, I'm convinced there’s still water trapped in the hull. She’s sluggish, feels heavy, I’m getting cavitation and she seems to be sitting stern / starboard heavy in the water.

I’ve spoken to Stewart @ Lymington who’s been great and I’ve drilled a few holes which has helped me get a lot of water out (pics attached) however I’m sure theirs is still water stuck in her.

Does anyone know the layout of the hull and where the baffles could be holding water please? I’m happy to drill some more holes but would rather know the layout before I do something stupid.

I’ve attached a pic of where I think the water could be being held back.

I’d be VERY grateful of help or advice please. Thanks!

** I should also note my fuel tank delaminated last year, so the fuel could have escaped into the hull from the original tank ?!

[Dry Run]

Hi, Don't know if I'm telling you something you already know

From our experience Scorpions have a bewildering system of drainage. The deck scuppers sit a few inches above the deck so do not drain anything other than a huge amount of water on the deck. The plug-hole type drain usually drains into a under deck compartment that has a bilge pump to evacuate deck water, This bilge pump often fails allowing the chamber to fill,with no means of escape (very annoying design). Forward of the drain plug is a white round inspection hatch. That leads to that chamber. You may also have a manual pump on the stbd side of the rear seat. I'd start by checking in there first - it can hold a lot of water.

Hope that helps

[Millermob]

Hello,

I think every Scorpion owner who has had a failed bilge pump has suffered from this issue.

Do you have the deck hatches as per my photo? (Two round white hatches on the deck)

Fore hatch is fuel tank inspection from memory, and the rear one has a bilge void with a bilge pump. If you’ve had a battery fail, both the hull void and underbench / splashwell will fill.

Hope that helps without having to drill anymore holes!

[gtflash]

I had the same on one. See "self draining like the titanic" on here. I have since fitted a nice posh bung to bottom of both I have owned. They are worse on land!

On previous boat I had trapped water under middle bilge pump (deck water), found to be the flat bit of timber they put across the V to create a flat bilge area. Water was trapped under that. I ended up using a wet and dry hoover on that one till bone dry then resealing.

Also I had water trapped to side of stringers (similar to where you drilled holes) possibly. It was a Long time ago but from memory I had to drill into stringers.

Cable ducts are square pvc drain pipe mounted to bottom of deck. They can also fill with water, but you can usually hear that by slapping some cables around. And listening for slosh.

Can you get its nose up very high?

The stringers usually form the inner most edge of the front locker and travel parallel backward to where transom knees would be and the side of aft bilge area. The deck is sandwich construction and only 10-15mm thick in most places. but in the majority of the areas there are two decks in theory. With cable trays in between them. The bottom out of sight deck is fuel tank roof and a potential water trap. Tank begins somewhere forward. Sometimes front locker rear wall and travels to rear locker front wall or front wall of middle bilge. I drew a very crude picture on here once on iPhone. Worth a search

What' did you do with tank? Has repair changed boat structure?

[gtflash]

Maybe water trapped other side of stringer? Outside the stringer which is 4 ish inches thick. Same width as knees. The V cuts in there. Be careful if you decide to go through stringer and out the other side.

[gtflash]

Reminded myself.

https://www.rib.net/forum/f8/drain-plug-70778.html