Cambodia's 1900km of navigable waterways are a key element in the country's transportation system, particularly given the state of many roads and the railways. North of Phnom Penh, the Mekong is easily navigable as far as Kratie, but there are no longer regular passenger services on these routes as the roads have taken all the business. There are fast-boat services between Siem Reap and Battambang, and Tonlé Sap Lake is also navigable year-round, although only by smaller boats between March and July.
Traditionally the most popular boat services with foreigners are those that run between Phnom Penh and Siem Reap. The express services do the trip in as little as five hours, but the boats between Phnom Penh and Siem Reap are horrendously overcrowded and foreigners are charged almost twice the price of Khmers for the 'privilege' of sitting on the roof. It is not the most interesting boat journey in Cambodia, as Tonlé Sap Lake is like a vast sea, offering little scenery. It's much smarter to take a bus on the new road instead.
The small boat between Siem Reap and Battambang is more rewarding, as the river scenery is truly memorable, but it can take forever. Whichever fast-boat journey takes your fancy, you may well end up on the roof so remember to use sun block and wear a head covering.
There are now longtail rocket boats operating on northern stretches of the Mekong between Stung Treng and the Lao border. These are super fast, but are super dangerous if overcrowded or travelling after dark. Never risk departing late if it means travelling at night.
The range of road transport is extensive in Cambodia. On sealed roads, large air-conditioned buses are the best choice. Elsewhere in the country, a pick-up truck, share taxi or minibus is the way to go.
Bus services have come on in leaps and bounds in the last few years and the situation is getting even better as more roads are upgraded. The services used most regularly by foreigners are those from Phnom Penh to Siem Reap, Battambang, Sihanoukville, Kompong Cham and Kratie, and the tourist buses from Siem Reap to Poipet.
There is a clean and comfortable bus service to towns and villages in the vicinity of Phnom Penh, such as Udong and Phnom Chisor. Operated by Phnom Penh Sorya Transport, these services are very cheap and English-speaking staff can direct you onto the right bus.
Minibuses serve most provincial routes, but are not widely used by Western visitors. They are very cheap, but often uncomfortably overcrowded and driven by maniacs, like the meanest of matatus (minibus taxis) in East Africa. Only really consider them if there is no alternative.
Car and motorcycle rental are comparatively cheap in Cambodia and many visitors rent a car or motorcycle for greater flexibility to visit out-of-the-way places and to stop when and where they choose. Almost all car rental in Cambodia includes a driver, which is good news given the abysmal state of many roads and the prominence of the psychopathic driver gene among many Cambodian road users.
If you are travelling in a tourist vehicle with a driver, then it is usually insured. When it comes to motorcycles, many rental bikes are not insured and you will have to sign a contract agreeing to a valuation for the bike if it is stolen. Make sure you have a strong lock and always leave it in guarded parking where available.
Do not even consider hiring a motor