Anyone bought any from say Walmart or somewhere liek that and installed theM

Unless your willing to spend the big bucks it's a gamble. I bought three strips from -bay to put on my toon and they've lasted for years exposed to the weather. I bought two more to make some attractor lights and they lasted all of two minutes. The safe bet is to pay for a quality product.

BluewaterLED is a site sponsor. Lifetime guarantee. I have Bluewaters on my trailer and superbrightleds in the boat 

I have not added extra lights, but i did upgrade the lights that came in boat to brighter LED bulbs. Made a big diffrence, much brighter now. 

I would advise against the walmart ones. Last I've checked I think they were like $12-15 for 2 1 foot strips. If you're looking to light your boat up on the cheap go for the ones on ebay. Yeah they aren't as high quality as something like a Bluewater, but for the price they can't be beat. When I bought them for my last boat, I didn't pay more than $3 per 1 meter strip and that was including shipping. I did the trailer for that boat as well, and that ran me under $40 with 2 16' sections. $10 of that price was for the waterproof switch I mounted on my trailer to turn them off for over the road. Best advice I can give you is just put some silicone over the cut ends and over the end the wire comes out to make sure they are sealed.

This is what my other ride looked like when done: