Internet Access Conundrum

OK, we've bought a single-device weeklong package through the cruise planner. I'm now re-thinking this and am still not sure I really need to use my own device. It might be more advantageous to just buy daily access and use the "internet cafe" (or whatever they call it) on board. I don't need access on the first or last day. So does this scenario work?

Day 2 pay $20

Day 3 pay $20

Day 4 pay $20

Day 5 use Diamond free day (self)

Day 6 use Diamond free day (spouse)

FWIW we are not really married to our smartphones, so do not expect to do alot of communicating that way while cruising.

Use the D coupon the second day, Then, on day three buy the remaining days package ($13/day) and apply the second D coupon ($20).

Or use your D coupons on sea days and find WiFI hot spots in the ports (and spend nothing on the ship).