Where is the best place on the deck to drill a hole for a water fill? I plan on putting a 10 gallon hard tank just forward below the galley on the port side. I have a 1999 26X. Thanks in advance!

I just got a 1999 26x. I have a question about the backstay? When the boat is rigged the upper and lower shrouds are tight and the headstay is tight as well ( it has a roller furling jib) the mast has a 2" to 3" bow towards the stern but the backstay is very loose. Is this right? I would a...