Hi bjo... Sticking down the deck is the biggest and most delicate task. You will have been building the boat upside down on the deck, then this has to be stuck down in one go onto the hull.
That means you have to carefully place 2 metres of glue onto the lip of the hull and then clamp the whole thing together til it dries.
Stablit express is an excellent gap filling glue but it goes off in 15 miuntes! It will take that long to put all the clamps on.
I would first suggest in fact it is a must, to go through the whole procedure without glue as a dry run, get the clamps pegs, whatever ready.
Use long lengths of small section wood, placed around the deck edge, to make sure the deck is held down evenly in position and that there is no wavy line showing where the clamps were.
I would be tempted if doing it again to use a transparent sealant instead. You can be sure of a good joint and also if you cock it up have another go. It was a near thing for me!
Just in case you have not put large decals on before they go on wet.
best regards, Roy