I engineered this solid wood bow filler the other weekend, if you like I can send you the plans.
Only 2-3 splinters so far.
I used to have the integrated bow sac, with a splitter valve from my center locker filling it. So little water would get in there it was a bit of a waste, many times I would just leave it filled for months at a time to avoid filling/ draining. I always ran an additional large sac(550 lbs) in the walkway to make up for the lack of weight the integrated bow sac produced. That pretty much defeated the purpose of having the integrated bow sac as I had to fill the 550 with the fat sac pump.
For a while I just took the integrated bow sac out from under the seat and threw it on top of the seats. This worked much better, but still not enough weight and still required a few hundred lbs of lead to counter weight the sacs & people in the back. It did open up space in the walkway for backpacks, boating sodas, etc.
I now tow with a old truck w/ a questionable engine and am trying to eliminate as much lead weight as possible without impacting the wake in any way. Therefore I went with the triangle sac.
What I would really like would be a triangle sac w/ and extra 'rectangle' on the bottom that also fills the bow space to the floor. I think that would be the perfect amount of weight and I could ditch the last of the lead.