Hello! That sounds like an exciting trip to Kenya. Here are some travel tips to help you plan your journey:

Best Time to Visit:
The best time to visit Mombasa, Malindi, and Watamu is during the dry seasons, which are from January to March and July to October. During these periods, the weather is typically hot and dry, making it ideal for beach activities and wildlife viewing.

Route and Accessibility:
The most common way to reach Mombasa is via Jomo Kenyatta International Airport in Nairobi and then a domestic flight to Mombasa. From Mombasa, you can reach Malindi and Watamu via road which provides scenic views of the Kenyan coast. Public transportation and taxis are widely available for local commuting.

Accommodation and Booking:
There's a wide range of accommodation options available in these cities, from luxury resorts to budget-friendly guest houses. You can book through various online platforms like Booking.com or Airbnb. Remember to book in advance especially if you're traveling during peak season.

Clothing and Essentials:
Pack lightweight, breathable clothing. Don't forget your swimsuit, sunscreen, hat and a good pair of sunglasses to protect yourself from the hot sun. Also consider packing a strong insect repellant due to the presence of mosquitoes.

Health and Safety:
Get all necessary vaccinations before your trip and consider travel insurance. Follow local advisories and news broadcasts to ensure your safety, particularly regarding weather or political situations. Always drink bottled water to avoid any waterborne diseases.

Local Etiquette and Respect:
Kenyan people are generally friendly and helpful. Dress modestly, especially when visiting religious sites. Remember to ask for permission before taking pictures of locals. It's also good to learn a few basic phrases in Swahili, the local language.