Any nice lakes near lauterbrunnen

Lauterbrunnen is a short train ride away from Interlaken (which you'll have to go through to even get to Lauterbrunnen). Interlaken sits between two large scenic lakes: Lake Thun and Lake Brinez. You can take boat tours on either lake.

Excellent would you recommend going on a half a day tour and then stay there and sight see ? Can you go to the lake and hangout have a drink and eat ?

You will travel along Lake Brienz when you arrive from Luzern to Interlaken, and might pass Lake Thun later, depending on your next destination. If you decided to go with a Swiss pass, then the lake boats are covered on the same days that you're counting for train travel, or they're discounted 50% on the in-between days of a flexi pass.

Yes I will have the Swiss passes so I all be covered for the boat tour ?

Yes, you can go on a boat tour on on one of your pass days. Be aware, though, that if you'd like to sit on the top deck you will have to pay a small surcharge for first class. If the day is nice, I'd definitely sit on the upper deck. On Lake Brienz, I like to have lunch at Grandhotel Giessbach, which is itself a sight to see. Have lunch out on the terrace by Giessbach Falls.

There's a new jet boat ride on Lake Brienz... see http://jetboat.ch.

That Jetboat looks like fun, but somewhat on the expensive side!

There's a new jet boat ride on Lake Brienz... see http://jetboat.ch.

BAH HUMBUG - BAH, I say, HUMBUG

That's the LAST thing that beautiful lake needs. Lovely serene beauty, beautiful waterfalls, the occasional steam whistle of the historic old steamship, gently chugging from village to village, the sky reflecting in the still deep glacial waters with the beautiful colours, the lovely forest all around topped by the white crowned majesty of the mountains.

Interrupted by the noisy messy din of a screaming jetboat. Right. Just what we needed.