New Owner / Hull 355 / Pop Top Mast Slug ? / Keel Hole / Cockpit cubby

Apr 30, 2021
Sirius 21 Pakenham
Just purchased hull 355 / Doing a full recondition over the next few months.
Mast Slug: I am presuming the mast slug with threaded extension is to hold the top top while up. Mine seems to be bent out of shape. Is this supposed to be straight. Is the pop top just held against the mast with a wing nut?

Mystery hole at top of Keel trunk. What is this hole for. Goes through to the other side. Maybe a stop pin?


Open cubby by starboard lazaret. This seems like it would just hold water. No drain. What is it's intended purpose?
The inspection port seems to have been added to gain access to the lower rudder dungeon bolts. A tunnel right through the foam.

Last edited:
Jun 19, 2020
Mcgruer Sirius 21 Camden
Top pic
That’s how my pop top is held up
Just a wing but on a threaded bolt( that’s also bent) works ok
Jun 19, 2020
Mcgruer Sirius 21 Camden
I also had the same thought about that open compartment on the starboard side of the stern. No door, no drain
May 14, 2009
Sirius 21 Pelican Yacht Club, Manitoba
My pop top is held by a wingnut on a bolt through a square piece like yours.
The bottom bolt on your keel trunk is what the keel swivels on. Top hole is for a lockdown bolt. This should be aluminum so it can sheer.
The open cubby on aft starboard side is for your fuel tank.
I've had my Sirius since 2009. Contact me any time with questions or manuals.