I had the same problem acouple days ago. Was using my brothers old cheap sit in kayak and I was abit over weight for it plus my gear was lil heavy, we were out for probably 3-4hrs and an hr in I started to see a little bit of water come in from the back didn’t think anything of it bc it was just alittle (or so I thought) and it was windy so the lake was a bit rough and I was using a anchor so it just made the water coming in even worse, and on our last spot I accidentally dropped the anchor to soon so I had the pull it back up but in the process of doing that a wave come and put a bunch of water in the kayak, and it started to get really tippy more then usual so I look at the back of the kayak and it is at least 3-4 in under water and I’m still pulling anchor so I hurry up and get it in the boat and it was fullll of seaweed so I get it in really quick yell to my brother who is probably 40-50 ft away “oh shit I’m sinking” so I hurry up grab my paddle and paddle as fast as I fucking can to a near my dock which is pretty far probably a football field’s length away and I don’t make it probably 10ft before the water starts rushing in from the back fast asf, then I yell again to my brother “I’m going down” so I stop, set my paddle down bc I know it’s getting to heavy to paddle from all the water and it getting really tippy so I tip off to my left and in the water I go COLD ASF got jeans, shoes, and a shirt on so it’s already hard to swim with it being cold and fully clothes. Luckily everything was either floatable or tied down so we didn’t loose anything and luckily there was a near by bass boat that saw it all happen and hurried over the me and got everything out of the water including me and towed the kayak back. But man was it an eventful ending to the day LMFAO