Improving the v-berth with 4" Foam

This weekend I'm installing a new 4" foam layer in the v-berth - which should substantially improve my sleeping experience.

LUCID 4 Inch Gel Memory Foam Mattress Topper - Ventilated for Optimum Temperature - King
$149.99 as of 2018-04-25
https://www.amazon.com/gp/product/B01N1NV1HZ/