The water and sky should have close exposure readings since the water is a reflection of the sky. And in your picture, they have similar 'brightness'. Maybe the dark mountain range is confusing your camera's meter. Check if your camera has a HDR setting. That's 'High Dynamic Range'. That will pull in more detail in the shadows while not blowing out the highlights. If your camera has it, see if you can select levels, because sometimes HDR can look cartoonish if applied too high. If you can select levels, pick a low one. I would also shoot in manual exposure that way your exposures won't jump around depending on what your camera is pointed at. The exposure 'weight' is often connected to the focus area you select when you're in Automatic exposure. Choosing a manual exposure will avoid settings that jumping around. Select an aperture like f7 or f11 because it looks like you're going for a lot of detail. The corresponding shutter speed might be too slow for handheld at dawn so use your tripod/monopod, or set your camera on a fence post or tree stump, or lean against something immobile like a tree or side of the barn. A useful and cheap accessory is a bean bag that you can place your camera on so you if you're using a tree stump or fence post (or tractor wheel, car hood, etc) you can avoid the shakeys and you're setting your baby down on something soft. I would also set your focus to manual that way, you can avoid your lens hunting for focus in the dim lighting of dawn. The focus mechanism needs things of high contrast to work best. Since contrast is low in the dim light of dawn, it's going to zoom in and out trying to lock on something. I think it's easiest if you just focus manually. If you were focusing on the mountain ranges or the sky, you can set the focus on infinity.
Another option is if your camera has multiple exposure capability. That allows you to take two or more frames - exposing for the sky (which turns the land black due to underexposure), and then exposing for the mountains (which blows out the sky), then camera's software combines them and you get the best from the separate frames. I think you might have it because you mentioned bracketing. Look for Auto bracketing and Multiple exposure on the Drive setting.
Good luck! Photography is fun! Confusing when you're learning, but always fun!