I would like to expand my photo horizons from Nikon 35mm to either MF or LF primarily in landscapes, seascapes and other scenery by exploring on foot as well as on my 30' sailboat.

Could you make a recommendation for a camera to use?

I almost bought a Deardorff 5x7/4x5 but am still reluctant since it may be a bit cumbersome on the boat. I have also been advised to consider Rollei 6001 (since Hassy is a lot more $), Bronica ERTS/SQA(?) and Mamyia 645.

Your comments and recommendations would be greatly appreciated.