Y-bom floats – optimal mooring and safety in the marina

Kristof
Jun 11, 2026
39

Professional management of a marina, sailing club, or a private jetty requires the use of safe and stable mooring solutions. Mooring fingers, commonly referred to as Y-booms, represent the standard in modern yacht harbors. They allow precise and collision-free parking of yachts perpendicular to the main dock. The heart of each boom, determining its buoyancy and stability on the water, is the dedicated Y-bom floats. Made of durable polyethylene using the rotational molding process, they provide optimal buoyancy and eliminate the risk of sinking heavy steel mooring frames, protecting the sailors' property and facilitating daily maneuvers in the marina.

The Crucial Role of Polyethylene Floats in Mooring Finger Constructions

The steel structure of a Y-boom has a significant dead weight, which would partially or completely sink without proper floating support. Y-bom floats perform a key hydrostatic task in this system:

Maintaining a constant lateral level: The floats ensure an optimal height of the boom above the water level. As a result, the Y-boom is always at the same height as the side of the mooring yacht, which facilitates disembarking and protects the hull from bumping.
High resistance to environmental factors: High-density polyethylene (HDPE) is 100% resistant to corrosion, salt water, diesel oils, and ultraviolet radiation. The material does not become brittle and requires no maintenance for decades.
Resistance to ice pressure in winter: Mooring fingers very often remain in the water all year round. The flexible polyethylene floats perfectly withstand the pressure of drift ice and freezing water, eliminating the need to dismantle the marina for winter.
Seamless, watertight construction: Rotomolding technology allows the production of a monolithic body without seams and joints, which guarantees full and absolute watertightness of the float, even under impacts.

FLAT or PROFI Version – How to Choose the Right Y-Boom Float?

The choice of the optimal float depends directly on the geometry of the metal frame of the mooring finger. Manufacturers offer two main construction types of floats:

Floats with a mounting channel (PROFI): These models feature a specially shaped longitudinal groove on the top wall (e.g. for a 100 mm profile). This allows a deep embedding of the steel frame inside the float body. This solution is mechanically extremely stable, protects the profile from moving, and allows for a very low profile of the Y-boom above the water. An example is the ponton 60x40x60 Y-BOM (SKU: PL604061PEBLUYbom), which is the most popular choice in modern marinas due to its dimensions and stability.

Floats with a flat mounting surface (FLAT): These floats feature a completely flat top surface. They are universally applicable and are suitable for constructions where the steel frame rests on the floats from above or is fixed with external clamps. They are ideal for older types of booms or custom designs, offering great freedom in positioning the attachment points.

Wskazówka eksperta: When planning the arrangement of floats on the mooring finger, the float with the larger buoyancy should be placed at the very end of the Y-boom (water side). It is precisely there, when mooring the yacht and tensioning the mooring lines, that the greatest vertical and torsional forces occur. Additional buoyancy at the end prevents a dangerous nose-diving of the boom under water when the crew boards.

Technical Comparison of the Most Popular Y-Bom Floats

The following table compares the dimensions and buoyancy of mooring floats dedicated to professional marinas:

Float Name (Product Link)	SKU	Dimensions (L x W x H)	Top Construction	Usable Buoyancy
Y-Bom float 60x40x60 black	PL604061PEBLUYbom	60 x 40 x 60 cm	With profile groove	approx. 130 kg
Y-Bom float 60x40x61 black FLAT	PL604061PEBLAYbom	60 x 40 x 61 cm	Flat (FLAT)	approx. 130 kg

By using polyethylene floats for marina construction, you can be sure that the docks and fingers will stably maintain their swimming line for many years. It is an economical and maintenance-free solution that increases the prestige and safety level of any modern marina.

Frequently Asked Questions (FAQ)

Will Y-bom floats be damaged by freezing water?

No, the floats made of polyethylene are fully resistant to low temperatures and stresses generated by freezing ice. Their flexibility prevents cracking, allowing the structure to remain in the water for winter.

How do I choose the float: FLAT or PROFI?

The PROFI float has a groove for a profile (e.g. 100 mm) and is designed for steel frames inserted into the body. The FLAT version has a flat mounting surface and serves for frames resting on the floats from above.

What is the buoyancy of a single Y-finger float?

A standard float measuring 60x40x60 cm provides a net buoyancy of approximately 130 kg. This allows for safe support of heavy steel beams and access docks in the marina.