Garmin nuvi for lake maps?

[76starcraft115]

Will a garmin nuvi work w/ lake chips meant for marine units? Garmin says yes... But won't tell me the detail content. Does anyone have a nuvi with lake maps?

I looked this up before hand on here and all posts were from '08.

I do know that Garmin sells the nuvi 500/550 that is auto/marine and is waterproof, however the unit retails for 750+.

So I'm looking at a $100 chip and probably an ebayed nuvi...

Any comments or help is appreciated, thanks!