340 Rib Advise

[Locozodiac]

Bought a 340 Rib with 2 “drain plugs” on lower transom, one on top of the other, upper is a normal water drain plug, lower is a twist/screw removable type plug. The issue is : what is this weird second plug for ?

Understand that ribs have a 2 part deck, that is a lower & upper halve decks bonded together, will this plug be to flood water into deck/keel compartment to lower tubes better into water, this model looks very floatable once on water, see pics for a tech understanding. Any ideas ?


Happy Ribbing

[Poly]

Originally Posted by Locozodiac

Bought a 340 Rib with 2 “drain plugs” on lower transom, one on top of the other, upper is a normal water drain plug, lower is a twist/screw removable type plug. The issue is : what is this weird second plug for ?

Understand that ribs have a 2 part deck, that is a lower & upper halve decks bonded together, will this plug be to flood water into deck/keel compartment to lower tubes better into water, this model looks very floatable once on water, see pics for a tech understanding. Any ideas ?


Happy Ribbing

Top one drains the deck/cockpit.
Bottom one drains the hull/bilge.

Not normally used the way you suggest (Seariders do have flooding hulls intentionally) - but rather just to drain any water that accidentally finds its way under there.

[Locozodiac]

Originally Posted by Polwart

Top one drains the deck/cockpit.
Bottom one drains the hull/bilge.

Not normally used the way you suggest (Seariders do have flooding hulls intentionally) - but rather just to drain any water that accidentally finds its way under there.

Hello Polwart

What don't understand is : both decks are completely sealed like a glove, the only reasonable idea would be to drain flooded bildge in case you break the upper deck, how about flooding once on water with lower valve plug removed, once completely filled, place plug back to balance better rib ?

Happy Ribbing

[Poly]

Originally Posted by Locozodiac

both decks are completely sealed like a glove, the only reasonable idea would be to drain flooded bildge in case you break the upper deck,

Thats what everyone hopes - although there have been many threads on here with people trying to trace a small leak.

how about flooding once on water with lower valve plug removed, once completely filled, place plug back to balance better rib ?

The only ribs that do this intentionally (that I know of) have a much bigger hole, and holes at the front of the hull too. That way as the boat starts to lift onto the plane the hull cavity drains. People with those hulls often debate plugging the holes to improve performance.

When people complain about poor performance here they are often sent to check for water in the hull cavity meaning there is a massive weight there - so whilst your idea makes sense - its not going to help - especially if you want good "hole shot" for towing skiers.