RE: board taking on water
Can you describe your problem/issues a little better here..?
Normally the term "taking on water" means that water is getting into the foam core of the board and making the board heavier.
This would normally mean that the vent plug is not sealed or was never installed correctly, or the hull has suffered some damage that lets water get through the composite skin of the board and into the core foam.
Ships and boats that are "taking on water" are usually "sinking" as the water displaces the hulls normal buoyancy.
Your problem sounds much different.
Is the nose riding too high?
Is the tail riding too low?
Where is your mast foot in the mast foot slot (near the back I would hope for your weight on a GO 170 with a smallish sail).
Where do you have your footstraps placed, and are you using them?
Once up on a plane, your GO 170 should really take off if you are gettng into the footstraps and have them placed in the farthest back and outboard FS inserts.
Are you using a harness? Are you hooking in and putting your weight on the rig once you get into the footstraps?
Hope this helps,