CONTINUOUSWAVE

On my 1998 17 Outrage II there is a white plastic plug directly above the bilge pump that had three screws attaching it to the wall of the sump that is located directly behind the helm. I thought initially this hole had something to do with the bilge pump functioning. I'm not really sure what function this hole served to begin with, but was covered with what looked like a factory-type white plug that came with the original boat manufacturing.

I removed the screws and pried out a mushroom shaped plug, with a flat across its face and a stem that went into the hull.

With the plug now removed, about one gallon of water came out from this half-dollar-sized opening in the boat hull. The water that initially came out of hole had a brown tinge to it.

I peered into hole with the help of a mirror and could see pink fiberglass, but inside everything looked clean.

I may seal the hole with fiberglass. There are also spider cracks coming out from the hole. I can see this is where the water is probably entering into the hull area.

What may have been the original purpose of this hole and plug?

A guess: the hole (which is described as being original with the boat from the factory and having a cover that also appears to be from the factory) may have been a sprue hole.

A sprue hole is used in the fabrication of all Unibond hulls as a place in the liner mold where the foam is introduced into the then vacant space between liner and hull or a place where the expanding foam is intended to overflow and exit from the interior. Generally in either case, the foam would overflow as it expanded. The cured foam would then later be cut off to be flush, and a cap applied with adhesives.

Because there is some vacant space behind the cover in this hole, it may not have been intended as a sprue hole, or the foam may not have expanded completely in that area.

When you describe "pink fiberglass" I am thinking of something like attic insulation. Is this pink material a loose fiberglass or a cured resin-fiber mixture?

Your best answer may come from contacting Boston Whaler customer service, and asking about this to someone who has been working there since at least 1998, who would be familiar with the molding process for that particular model. There still are some folks that have been around that long, although now they are usually in senior positions, not first-tier customer support people.

Also, Phil T is expert on these boats, and he should be familiar with this detail in the hull.

I sold my 1996 Outrage 17II this past summer so I can't go look at it now, but mine had a drain for the fuel tank cavity. Based upon your description of the location of the hole in your boat, it matches my drain location. Mine had a thru-hull with internal threads directly above the bilge pump on the forward wall of the below deck locker aft of the helm seat. Normally this drain was closed with a screw in plug, but I removed it each fall to drain any water that accumulated in the fuel tank cavity.

VTVFR is correct.

The drain under discussion is the drain for the fuel tank cavity.

Do not alter or modify the drain or plug in any way.

Phil T wrote:The drain under discussion is the drain for the fuel tank cavity.

With the purpose identified for the drain, that some water came out upon removal of the plug makes good sense.

Thank you for your replies regarding this unusual hole.

I am convinced it is a drain coming from the fuel tank area.

Sue from Beacon Marine mentioned that there may be an O-ring that seats under the cap. I may try to pick up an O-ring.

There are also spider cracks coming out from the hole which I will attempt to repair myself—that will be interesting.

[The c.1998 17 OUTRAGE II boats] have a through-hull fitting on the starboard side of the transom. If this thruough-hull
becomes submerged—possibly due to weight—water will enter and possibly enter the rigging tunnel on the starboard side of the boat. If enough water enters the rigging tunnel, it will find its way to the fuel
tank cavity.

The only way to drain the water in the fuel tank cavity is to remove the referenced plug.

There definitely should be an O-ring on the fuel tank cavity drain plug. Install one if your boat is missing the O-ring.

When the plug or cap for the drain for the fuel tank cavity on a c.1998 17 OUTRAGE II boat is removed, what does the water drain into?

How is that water removed?

When the water is exiting this drain hole on the 1998 Outrage II 17ft it is going directly into the rear sump where the bilge pump can be activated to expel any water that has accumulated.

What is the basis for keeping the fuel tank cavity drain capped? Why not leave it open?

The fuel tank cavity drain plug is located near the bottom of the large storage box located below the deck near the stern of the boat. Water accumulates in this box from multiple sources. Without the drain plug installed, water will enter the fuel tank cavity. It is best to keep this cavity as dry as possible.