How will the den be used? Most bedrooms are used only at night, in the dark, when a view will be wasted.

Excellent point! And my kids tend to keep their blinds shut anyways because they are teenagers. Den would be a tv sitting area/game room/hangout for friends.

How wide is the view from the back to the waterfront? Meaning what is the width of the property?

What direction is the back of the house? East, west or whatever. What climate?

kids won't be living in those bedrooms forever, so think ahead. prob the den w/the view and one of the bedrooms. as one moves out, the younger one can have the 'view' room.

There is more to determining space location than what you share. Consider engaging a local competent architect that will help you design a home that meets your needs and fits your site, especially a waterfront home.

What will be the difference between the bedrooms and the den? In other words, will there be bathrooms attached to the bedrooms, but not to the den? Or are there marked size differences between the bedrooms and den? I only ask because if they are three rooms of more or less equal size, their usage could be changed depending on your needs or the needs of future homeowners, in terms of resale.

We have a beach house with ocean views from 4 out of 5 bedrooms. To me, being able to see the water from my bedroom is calming and the sound of the waves puts me to sleep. We have a upside down layout to take advantage of the views.

Teens are 't kids and designing for young people is short sighted. Design for people who will also be using those rooms. Most lake places have the views from the public spaces a priority.

If kids are teens sounds like they won’t be in the house for long. i’d plan for what you want long term. den area sounds like it could get more use in long run.

I say maximize the views! Right now we are changing our house plans to give all thr bedrooms a great view if possible. Great for resale value as well

If you are starting from scratch with a custom design for the specific site, then your scenario of choices has already painted you into a corner. Why can't all rooms have a view to water?

I'm trying to imagine your site and the view to the water but nothing's happening.

If you want us to offer real soultions, define the problem wiith a site plan, a google map and site photos.

Agree with @Mark Bischak, Architect For something this important you need to actually hire someone with design talent and have them show you the alternatives and then develop the best configuration for your home. That's what they get paid to do, same as you get paid for what you do.