Blanch lobster in boiling water for 6 minutes. Remove from heat. Put lobster on ice bath. Once cool, cut lobster into small pieces.
Cut the cleaned scallops into thin slices. Combine scallops and lobster in a bowl. Pour the citrus juices over scallops and lobster. Add the onions, tomatoes, cilantro, habanero, olive oil, ketchup, salt, and pepper. Mix gently to coat the scallops and lobster. Cover the bowl tightly, refrigerate for 4 hours to "cook".
Drain the juice, and arrange on plates. Garnish with fresh avocado and plantain chips.