BUP - 470 Mast, Boom, Spinnaker Pole and Deck Hardware

The 470 is one of the most technically demanding Olympic classes. Success is not only about sail trim and tactics. It is about understanding how mast section, taper profile, rig tension and geometry interact across wind ranges. Seldén has developed a complete 470 spar range in collaboration with top teams, offering distinct mast stiffness platforms and advanced customisation options. The objective is simple. Deliver repeatable bend characteristics, defined gust response and a tuning window wide enough for Olympic campaigns.

Mast Platforms

Seldén offers three stiffness platforms for the 470 class, each designed around crew weight and performance objectives.

Cumulus Standard – Reference Platform

Cumulus is the most widely used Seldén 470 mast section. It offers a balanced stiffness profile and controlled gust response, making it the reference platform for most teams.

Parabolic taper profile.
Excellent balance between stiffness, weight and dynamic response.
Championship-proven geometry.
Predictable fore-aft and athwartship behaviour.

For teams seeking a stable, well-understood tuning base, Cumulus Standard remains the default section of choice.

Cumulus Needle Taper – Extended Depowering Range

The Cumulus Needle Taper introduces a smaller, more flexible top section above the hounds. The result is:

Greater depowering range without losing lower-panel control.
Increased top-mast “whip” in gusts.
More dynamic bend profile in unstable wind conditions.
A wider tuning window across regatta wind ranges.

The Needle Taper is the evolution of the Cumulus platform. It is designed for teams seeking additional responsiveness while retaining the lower-section stability required for high-load upwind modes.

Zeta – For Lighter Crews

Zeta is the lightest and most flexible section in the Seldén 470 range.

Approximately 10% softer than Cumulus
Earlier gust response.
Internal sleeving for deck-level control.
Developed specifically for lighter teams.

Zeta allows lighter combined crew weights to access earlier bend and improved control without excessive pre-bend settings.

Alto – Increased Stiffness for Power Conditions

Alto is approximately 5% stiffer than Cumulus and was originally developed for marginal power conditions.

Increased fore-aft stiffness.
Favoured by heavier crews seeking extra light-wind power.
Strong lower-panel support.

Alto occupies a narrower use case within the modern fleet but remains a defined option for specific weight and venue profiles.

Engineering and Manufacturing Precision

All Seldén 470 tapers are CNC plasma cut and auto welded for consistency. Parabolic taper geometry provides relative stiffness at high-load lower sections and controlled flexibility toward the tip. All spars are heat treated in-house to increase hardness and resistance to permanent set. CNC drilling ensures T-terminal alignment accuracy to 0.1mm side to side for straight rig geometry For two-boat tuning and race/spare mast replication, this level of repeatability matters.

Customisation as a Campaign Tool

Olympic campaigns rarely operate with fixed geometry. Seldén supports advanced configuration including:

Needle taper integration.
Extended goosenecks.
Optional halyard locks.
Alternative tube weights.
Custom fitting positions.
Fully adjustable spreader systems.

This allows teams to refine bend behaviour, rake geometry and load distribution according to crew weight, sail design and target regatta conditions. The mast is not a static component. It is a tuning platform.

Booms

Ultima Boom

The Ultima section is optimised for maximum vertical stiffness within 470 class rules.

“Plank” profile with material concentrated top and bottom.
Reduced side wall thickness for weight efficiency.
Lower track eliminated to reduce weight and increase structural efficiency.
Fixed kicker and mainsheet geometry.
Extruded from Seldén XPS alloy for increased tensile strength.

Ultima is currently the most performance-oriented boom in the Seldén 470 range.

Olympus Boom

Olympus offers a slightly softer and lighter alternative while remaining competition specification.

Maximum width and depth within class rules.
High-load kicker slide.
Sliding mainsheet system.
Integrated 4:1 outhaul

42mm Tapered Spinnaker Poles

Seldén 470 poles use seamless double taper construction with 6082-T6 aluminium tubes for the lightest and stiffness poles available.

Central lift eye configuration options.
Beak up or beak down variants.
Seldén pole ends engineered for reliability under high dynamic loads.

The objective is minimal deflection under load and clean spinnaker projection downwind.

Integrated Performance Ecosystem

While mast selection remains the primary performance driver, Olympic campaigns also require:

Rig packs with repeatable geometry.
High-load vang systems.
Precision deck hardware.
Global spare availability.

Seldén supplies a complete ecosystem for the 470 class, allowing teams to standardise spars, hardware and rig components across training bases and regattas worldwide.