Laser LTV Water Drain

[Laser_LTV]

Hi Guys,
I am very new to the boating world and especially new to this style boat. I have an 84' Laser LTV 17' Bass Boat with a 94' Evinrude XP 150 off the back. I installed a jack plate and like everyone, trying to get the best performance out of the boat... So, the question to all the LTV owners on here is, the sides of the hull fill with water and I am curious if this is supposed to be happening? Is it for leveling purposes? I just notice that when the boat is on the water for 30+ minutes it digs deep when accelerating due to weight. I can't find any info online so I turn to you. Last year I had the boat on the lake near me and I got a call one Sunday morning from the dock manager saying my LTV was at the bottom of the lake... Luckily however, my motor was above the water being that it was only 2 feet deep. I did not have a auto-bilge at the time (BUT I DO NOW) and was curious if the water in the side sections of the hull had something to do with this. The boat was launched and kept on the water 2 weeks prior to this occurrence and we were pulling bass just the day before. Being that the boat sits so low in the water (do to this side section water not being bilged out) the waves came over the back of it and it was sank before I knew it... Please help, as far as I know, there is no way to bilge this water out once the boat is on the water. The only way to empty the water is to pull the "3" plugs after the boat has been pulled. Thanks for your help, I look forward to a great season!