Birthday party ideas

I have 2 boys. 10 and 1. My oldest will be 11 in July and my youngest made a year in April. We weren’t able to have the baby’s party because of quarantine. So I’m planning on just doing one big party in July for both of them. My oldest is obsessed with the Titanic and my youngest, I really don’t know. I need party theme ideas. I want to do just one theme, but nothing babyish and nothing too old for my youngest. I thought about a nautical theme, but I really don’t know.