Hydrofoil - Modern Passenger Boats - Disadvantages

Disadvantages

Hydrofoils had their peak in popularity in the 1960s and 70s. Since then there has been a steady decline in their use and popularity for leisure, military and commercial passenger transport use. There are a number of reasons for this:

• Hydrofoils are sensitive to impacts with floating objects and marine animals. If the hydrofoils hit something the boat will fall off the foils and this often creates a perception of increased danger. However, there have been hydrofoils operating in Hong Kong for 20 years and those waters are some of the most littered anywhere in the world and hydrofoils operate a relatively trouble free operation. The Hong Kong Marine department has online records of all accidents in its waters for those who would like more information on their operation. The second problem is hydrofoils are almost like sharp knives going through the water, normally fatally injuring any marine mammal (e.g. whales) they hit. This is in contrast to normal hulls which just slide over a whale with minimal damage to both.

• Hydrofoils are expensive to build. A vessel like the Boeing Jetfoil nowadays costs about 3 times the price of an equivalent catamaran passenger ferry. This prices them out of the market completely. More simple hydrofoils such as the Russian designed ones and those by Rodriquez in Italy are more competitive in price and are still being produced today for operation on ferry routes.

• It is a very conservative industry. Hydrofoils are still considered exotic by many commercial operators of high-speed craft and many will not take the risk of trying such exotic vessels when they have no experience operating them. Those that do have found benefit in their operation. For example the largest ferry operator in the world, Turbojet (Hong Kong) still operate 20+ year old Boeing Jetfoils because they remain the industry benchmark for passenger comfort in rough seas.

• They are technically complex and require high maintenance, which is what killed most military hydrofoil projects. The US Navy for example developed some of the most technically advanced hydrofoils around but they could never get them to be reliable due to the complex propulsion systems and ride control required. This eventually led to the suspension of their hydrofoil projects. Most other Navy developments followed the same fate. The Russian Navy still operates very large hydrofoils and have been successful in their designs, largely because they have opted for simpler systems which might not have the same performance as the US designs but are much more robust and reliable. In Hong Kong, the increasing maintenance cost of keeping the old Jetfoils running is resulting in these vessels slowly being phased out.