Sub-surface buoys

Fendercare Marine provides a wide range of sub-surface buoyancy solutions for its customer's applications.

We design and manufacture our sub-surface buoyancy solutions to suit the application and depth rating performance requirements of our customers, ensuring maximum product life and integrity at minimum cost. 

Fendercare Marine provides sub-surface buoyancy solutions for a range of applications, including:

  • Pipeline installation buoys
  • Modsyn™ top-up buoys, general subsea installation buoys
  • Transponder collars
  • Modular subsea buoys
  • Distributed buoyancy modules
  • Submersible/ROV/AUV buoyancy systems 

Sub-surface flotation materials:

The application dependant material parameters to sub-surface buoyancy includes the foam material which forms the core of the product, and the external coating. 


For shallower depths, we offer either high-density polyethylene foam or expanded polymer foam.

The significant benefit both these foams offer over polyurethane foam, which most other manufacturers will provide for these depths, is that the foams are of a closed cell nature. This means that if the outer skin of a shallow water buoy is breached, our customers can be assured that the result will not be a rapid and catastrophic absorption of water followed by failure of the product.

For deepwater applications, we formulate and process our own pure syntactic foam, into which we then introduce moulded macrospheres to reduce the weight and ultimately the cost of the product.

External coatings:

There are 3 main material possibilities for encapsulating the core of Hippo subsurface buoys:

  • Polyurethane elastomer is a highly abrasion-resistant, reinforceable coating which we can either spray-apply or cast around the foam core. For ultimate durability, this form of coating can be Kevlar™ reinforced
  • Rotationally-moulded polyethylene is a cheaper and more uniform method of mass-producing a protective shell for the foam core in applications where the resilience and flexibility of PU elastomer is not required
  • PU paint is mainly used in applications where the core material is resilient in itself but requires some level of protection from UV degradation

Pipeline installation buoys

Fendercare Marine's commitment is to design, manufacture and supply the best possible solution for your pipelaying buoyancy requirements, using durable materials that can be taken onto future projects, and which will require very little maintenance either during or between pipelaying projects.

To reduce tensions on both vessel and pipeline during installation, buoyancy modules are typically fitted. This can happen either on the laying vessel itself or on land if the shore pull system is being used. We deliver proven offshore technology which you can trust.

The main features and benefits of Fendercare Marine’s unique approach to pipeline installation buoys are:

  • Easily and cost effectively customised to suit specific project requirements
  • Extremely durable outer polyurethane elastomer skin
  • Kevlar-type skin reinforcement available as an option
  • Various foam densities available depending upon the depth requirement
  • Some exclusive foams available of closed-cell nature to eliminate risk of loss of buoyancy due to damage to the modulemodules designed to accommodate your preferred attachment and release system
  • Base designed to fit multiple different pipe sizes
  • One-piece or multi-module systems available

Bespoke sub-surface flotation:

Fendercare Marine's combination of subsea materials technology and processes allows us to design and supply products for a wide range of other subsurface applications. These can be as simple as a transponder collar, however, the types of projects we get involved in can also be as detailed as the consulting, design and manufacturing we were engaged to perform for the most complex sets of submersible buoyancy ever produced, our sister company JFD's deep search and rescue (DSAR) submarine rescue vehicle.

Other areas we have applied our expertise, include combined jumper/umbilical flotation and protection and distributed/riser buoyancy. For the vast majority of work of this type, there are no specification tables which we can provide to arrange standard data into a neat format. Our customers confirm their subsea design and operational challenges and work with us to develop a technically robust and cost effective solution – where we act as an extension of their own engineering capabilities.

We provide the application of our materials, our experience and our expertise to assist our customers in finding the best possible outcomes to their subsea requirementsContact us now with any bespoke subsea buoyancy needs.