Pool noodles are about the easiest things to displace some water.
Unfortunately, getting the sail up (race sail or not) from what you have described with the mast buried is
always going to be a painfull and physically taxing job.
If I remember the way I have done it and it all really depends on which way the mast is pointing.
If the sail is downwind of the board then drag the board back into the wind hopefully the current will push the sail and level it out.
If the sail is up wind of the board, try to get the leading edge of the sail pointing to the wind.
With the sail in the water the filled luff tube will have no effect on the weight of the sail, that pleasure awaits you when you try to lift the sail from the water.
If all else fails get the tip of the mast upwind then starting from the tip lift it from the water, try to control the direction of the sail as the wind may try to push it under the water again, gradually work your way down the mast as the luff tube empties.
Unfortunately there is a detrimental side to be a competent gyber, that is you don't get much practice at this type of recovery.
Just think Shark