In Kenya we've got the possibility of going to a Safari, chilling on the beach and going for a few dives each day. The boat trips are approx 15-20 mins according to most dive web-sites for beginner dive sites, so that should hopefully lessen the travel time out.
Mozambique might be more to your liking then.
Kenya--in fact, all of East Africa--is a fantastic place to travel and I've never been anywhere on this earth that impressed me more or made me feel so "off the grid" as I felt there. There are problems (also political ones) but the people will get into your very soul and change you. Travelling for 6 months in east Africa is like getting a tattoo on your soul that you carry with you for the rest of your life.
If you're going to be in the general area then I would recommend diving in Lake Malawi. Getting to Africa you can fly to Lilongwe instead of Nairobi and take the chance to dive in Lake Malawi, which aside from being warm and one of the biggest inland lakes on the continent, is also home to a variety of species of cichlids (colourful fresh water tropical fishes that are popular in aquariums) that only live wild in this *one* single place on earth.
I remember my first dive in Lake Malawi as well as I do my first dive in the Red Sea. They're very different but gave me equally fond memories.
R..