do I need a ring main?

[fjweaver]

I'm installing permanent shore power with a consumer unit RCD 40A 30mA with 2 mcb's (16A & 6A).

I'm only planning at the moment to use the 16a to run a triple socket by the chart table (port side) & a double on the stbd side of the boat in my cabin.

I'm planning to run a cable to each from the mcb - but is it neccessary to create a ring main?

I may want to add 1 more socket on the port side in the future so presumably it would be better at the time to make the port side into a ring main - instead of a spur off a spur?