Many marina owners are faced with the challenge of how to determine the fair cost of a major capital investment such as a new floating marina. The actual product is a combination of structural and civil engineering, geotechnical and environmental considerations along with complex social issues throughout the increasingly detailed approval processes. After myriad issues one can hear the collective sigh of relief that the life cycle of such structures exceeds 20 years.
Given the size of the investment we like to suggest some care goes into the early choices that set the foundations of ongoing cost of ownership and maintenance. Many of these issues are covered in our book Sustainable Marina Development published recently. The primary choice is the site and this is critical with an old adage being that if the location is somewhere that is a safe anchorage, then that is the first clue to being a good marina site as well.
Once the site is closed and secured the issues turn to the type if floating berths and how they are secured in place. The primary consideration in floating berths is to have enough mass to minimise passing wakes or waves that cause movement in the marina. This movement translates into maintenance and therefore cost, so a smooth site is a happy site for all concerned. Heavy concrete marinas exceed 300kg per square metre and this serves to make the site very secure by ironing out surface chop. It will not stop a major swell and cannot make a bad site into a good one.
Sometimes metal decked systems with bolted flotation is preferred. This is useful where current or floods are a consideration as the gaps in the flotation are useful to allow debris and current to pass by the structure. The mass may be less than concrete however the system is designed with strong metal connections that hold the whole system in place.
Regardless of the system that is chosen the elements need to be good quality with a well thought out design. Services should be easily accessible and have redundancy to allow for future technology and growth in demand. Cleats need to be designed to break prior to the marina pontoons and in this way minimising damage and repair costs. This may seem unnecessary until a boater powers out of a berth with a line still connected; yes it does happen!
Overall marina design has progressed in many ways over the past 50 years and today’s quality floating platforms provide welcome harbours for vessels. Add to this the social atmosphere that attracts people and marinas are a valuable part of the urban landscape.