What Foil Assist Setup Do I Need for My Weight? Board, Foil & Power Guide

Updated for Gen 2.5: Foil Drive MAX+ now replaces the earlier MAX as the current all-rounder, with Fusion the higher-capability option. The choice still starts with rider weight, skill, board efficiency and how the motor will be used. Compare current Foil Drive systems.

Foil Assist works brilliantly when the complete setup is matched properly.

That last bit matters.

Buying the most powerful motor or smallest foil does not automatically create the best Foil Assist setup. Rider weight, board efficiency, front foil size, propeller choice and existing foiling skill all interact.

A 65kg prone foiler using a 900cm² foil needs something completely different from a 105kg rider wanting easy light-wind wingfoil starts.

As rider weight increases, we generally want more foil support, more efficient board volume and potentially stronger low-speed thrust. But the aim should still be to create an efficient foil setup rather than asking the motor to compensate for badly matched equipment.

This guide focuses mainly on Duotone Foil Assist, with comparisons to Foil Drive where that route makes more sense.

Quick Foil Assist setup guide by rider weight

Rider weight	Board direction	Front foil direction	Assist priority
Under 70kg	Efficient 35–48L+ board depending skill	Approx. 900–1100cm² for competent foilers	Keep weight and drag low; standard 2-blade often enough
70–85kg	Mid-length around 48L+ depending ability	Approx. 1100cm² or larger	Balanced all-round setup
85–95kg	58L+ efficient board	Approx. 1100–1350cm²+	More take-off support; prop choice becomes more important
95–110kg	58–78L+ depending skill	Approx. 1350cm²+ or larger progression foil	Prioritise board release, foil lift and sufficient thrust
New to foiling	Maximum confidence and useful volume	Larger, low-speed foil such as Free 1500-style setup	Consider Foil Cruise rather than a performance Assist setup

These are starting points, not fixed rules. Experienced riders can use considerably smaller boards and foils than somebody of identical body weight learning their first controlled flights.

The most important distinction: are you already a foiler?

Before discussing rider weight, answer this:

Can you already control a hydrofoil confidently?

If yes, the standard Duotone Foil Assist eMast AL or premium D/LAB route makes sense.

If no, the more confidence-oriented Duotone eMast AL Cruise deserves serious consideration.

Foil Assist can help a good foiler get more take-offs. It does not remove the need to control pitch and ride height once the board lifts.

Duotone Foil Assist AL: best-value performance route

The standard Duotone eMast AL uses an 84cm aluminium mast with the motor integrated into the mast.

Duotone recommends a foil front wing of around 900cm² or larger and a board of at least 35 litres as a baseline for this performance-oriented platform.

Those are minimum system recommendations rather than a promise that a 100kg rider will be comfortable on a 35-litre board.

For most customers we size the board around the rider and intended start method, not the minimum that will physically work.

Duotone Foil Assist D/LAB: best for experienced performance riders

The Duotone Foil Assist D/LAB is the lighter carbon-mast version.

Choose it if:

• you already foil well;
• you are sensitive to mast stiffness and drag;
• pump efficiency matters;
• you want maximum natural foil feel;
• you are prepared to pay for the performance gain.

D/LAB is not the automatic choice for a heavier rider. Rider weight may increase the importance of stiffness, but it may also make board, foil and propeller choice a higher priority than saving mast weight.

Duotone Foil Cruise AL: best if easy progression matters most

The Duotone eMast AL Cruise uses a slightly shorter 80cm mast and places the motor lower down.

The complete Cruise route can be paired with a larger, forgiving foil such as the Free 1500 and more board volume.

This makes more sense for:

• newer foilers;
• riders wanting calm assisted cruising;
• heavier riders who value stability over minimum equipment size;
• families or shared setups;
• people for whom learning ease matters more than ultimate pump performance.

Best Duotone Midfish size by rider weight

The Duotone Midfish 2026 is a particularly good Foil Assist partner because the longer, narrower shape builds speed efficiently before take-off.

Midfish	Volume	Duotone recommended rider weight	How we see it
5'2	38L	Up to 80kg	Performance option for lighter, competent riders
5'5	48L	Up to 85kg	Excellent lighter/midweight Foil Assist board
5'8	58L	Up to 95kg	Very useful all-round assist size
5'11	78L	Up to 110kg	Best for heavier riders or anyone wanting easier starts

Notice that these are recommended rider weights, not beginner buoyancy recommendations.

A 78kg expert may happily use the 5'2. A 78kg rider learning assisted foiling may be much happier with considerably more volume.

Under 70kg Foil Assist setup

A lighter competent rider can keep the complete system relatively small.

A sensible performance direction might be:

• Midfish 5'2 or 5'5 depending skill;
• 900–1100cm² efficient front foil;
• standard AL or D/LAB eMast;
• standard 2-blade propeller to begin with.

At this weight we would avoid adding thrust simply because a more powerful propeller exists.

If the setup already launches cleanly, preserving glide is usually more valuable.

70–85kg Foil Assist setup

This is the middle of the range where the standard Foil Assist package concept works particularly cleanly.

Look towards:

• Midfish 5'5 or 5'8;
• approximately 1100cm² or larger front foil depending discipline;
• standard 84cm AL mast for value;
• D/LAB for riders chasing minimum drag and better response;
• 2-blade propeller for the cleanest starting point.

If you are already a competent foiler, there is no reason to oversize everything simply because you are adding assist.

85–95kg Foil Assist setup

This is where board release and foil support become more important.

A very sensible Duotone route is:

• Midfish 5'8 58L;
• Glide-style 1100–1350cm² front wing depending skill and conditions;
• AL or D/LAB mast;
• 2-blade SLS or 3-blade considered where stronger take-off thrust is genuinely needed.

The current Duotone Foil Assist Complete AL with Midfish is available in matched board/front-wing combinations, which removes much of the compatibility guesswork.

95–110kg Foil Assist setup

For a heavier rider, our first instinct is not simply “more motor”.

We first look at:

• does the board accelerate cleanly?
• is there enough volume to start efficiently?
• does the foil lift at an appropriate speed?
• is the foil too small for the intended conditions?

A Midfish 5'11 at 78 litres can make significantly more sense than trying to force a very sinky board onto foil with throttle alone.

A larger efficient foil or Free-style progression foil may also be the better answer.

Once those pieces are correct, stronger propeller options can become extremely useful.

Does a heavier rider need the 3-blade propeller?

Not automatically, but heavier riders are more likely to benefit from it.

The Duotone Foil Assist propeller guide explains the full difference.

In simple terms:

• standard plastic 2-blade: calmest, most forgiving starting point;
• SLS aluminium 2-blade: more performance without giving away too much natural feel;
• 3-blade SLS: more low-speed drive for heavier riders, smaller foils and difficult starts.

Riders around 90kg+ become increasingly likely to gain something useful from the extra low-speed drive of the 3-blade, particularly if they are using smaller foils or sinkier boards.

That does not mean every 90kg rider needs one.

Does a bigger foil save battery?

Potentially, because an efficient foil that takes off at lower speed can require less sustained motor effort.

But there is a trade-off.

A very large foil also creates more drag once moving quickly.

The ideal setup is not necessarily the biggest front wing. It is an efficient foil correctly sized for the rider and discipline.

Should heavier riders choose Foil Drive MAX+ or Fusion instead?

Sometimes. It depends on more than body weight: consider the length and efficiency of your board, the size of the front wing, how good your take-offs already are and whether you want short bursts or prolonged powered riding.

Foil Drive Assist MAX+ Gen 2.5 is now the current all-round Foil Drive system, rather than the original Assist MAX Gen 2. It is a useful starting point for strong assisted launches and mixed surf, wing and downwind sessions. For heavier riders, repeated flatwater starts or more continuous power, the Foil Drive Fusion deserves a direct comparison.

As a guide, riders around 70–90kg should first consider board and foil efficiency before automatically stepping up in motor size. Around 90–100kg, MAX+ and Fusion are both relevant depending on use. Above 100kg, Fusion becomes particularly worth evaluating if assistance demands are high. These are not strict rider-weight limits.

Duotone's integrated mast can still be an excellent choice for a heavier rider who values low-drag foil feel and has a suitable board and wing combination. See our updated Duotone vs Foil Drive comparison or complete Foil Drive buying guide.

What Foil Assist setup for someone completely new to foiling?

This deserves a different answer.

Do not size the setup as if you already prone foil.

Use:

• more board volume;
• a larger, predictable foil;
• the more confidence-led Cruise mast;
• a propeller guard where appropriate;
• proper coaching and suitable conditions.

The Duotone Foil Cruise AL Complete Set is designed around exactly that easier direction.

Why board efficiency beats brute force

This is probably the biggest lesson in Foil Assist setup.

A longer board that releases cleanly can transform the amount of throttle required.

That means:

• easier take-offs;
• less battery consumption;
• less pitch drama;
• less need for maximum propeller thrust.

The motor should assist a good hydrodynamic setup, not rescue a poor one.

Try Foil Assist at Lymington

Foil Assist is exactly the sort of product where buying from specification sheets alone is difficult.

Through Try It Now at The SUP Co x Lymington, selected Foil Assist equipment can be available for suitable prospective buyers, subject to experience, approval, conditions and demo availability.

We can also help compare Duotone against Foil Drive and other Foil Assist systems rather than forcing every rider into the same platform.

Finance and complete Foil Assist packages

Foil Assist is a significant purchase.

Finance options are available on qualifying orders, which can be useful when investing in a complete setup.

Read the current options on our finance page. Finance remains subject to status, qualifying products and provider approval.

Foil Assist setup FAQs

What Foil Assist setup should a 70kg rider use?

A competent 70kg foiler can often use a relatively compact board and foil, for example a Midfish around 5'2–5'5 and a 900–1100cm² efficient foil. Skill and discipline still matter more than the weight number alone.

What Foil Assist setup should a 90kg rider use?

We would normally look towards more board efficiency and foil support, for example a Midfish 5'8 and an approximately 1100–1350cm² front foil depending on skill. Stronger propeller options may also become useful.

What Foil Assist setup should a 100kg rider use?

Do not undersize the board. A 5'11 Midfish-style board and larger efficient foil can be a much better starting point. Once board and foil sizing are correct, additional propeller thrust can help with take-offs.

Do heavier riders need more Foil Assist power?

Usually they need more overall support, but that should come from the complete system: board efficiency, foil area and motor thrust. More power alone cannot fully compensate for a badly undersized board or foil.

Should I choose Duotone Foil Assist AL or D/LAB?

Choose AL for excellent performance and value. Choose D/LAB if you are an experienced rider who values lower mast weight, stiffness, reduced drag and maximum foil feel.

Is Duotone Foil Assist suitable for complete beginners?

The performance Assist system is primarily aimed at people who can foil or are progressing into foiling. Complete beginners should look carefully at the more confidence-oriented Foil Cruise setup, larger boards, larger foils and proper tuition.

Can I try Foil Assist before buying?

Selected technical equipment may be available through The SUP Co x Lymington Try It Now service for suitable purchase prospects, subject to approval, conditions and availability.

Need us to build your Foil Assist setup?

Send us your weight, board, current foil, ability, discipline and what you want Foil Assist to solve.

We can help choose the board, foil, mast, adapter and propeller as one complete system.

Browse all Foil Assist systems or the dedicated Duotone Foil Assist range.

Comparing MAX+ and Fusion? Read Foil Drive MAX+ vs Fusion alongside our motor-height guide to check thrust, motor depth and installed cable geometry. Choose the complete board, foil and assist setup rather than buying components independently.