The St Lawrence 13

Honest three-way comparison:

13 ft (this spa) — compact entry. 390 × 226 × 120 cm · 3 adults · 3 × 5 HP pumps = 15 HP · single heated zone. Smallest footprint in the range. The 15 HP current is strong for exercise-against-flow, aqua jogging and resistance training; the included swim tether is typically essential for sustained stroke work on a 390 cm shell. Shallower at 120 cm (vs 137 cm on the 16/20). The compact-entry proposition — first-time swim-spa buyers, smaller gardens, 3-person households.

St Lawrence 16 — the flagship. 500 × 228 × 137 cm · 7 adults · 1 × 4 HP + 3 × 5 HP = 19 HP, the ceiling of the Balboa control system. Full 19 HP routed into the swim end — strong enough for stroke swimming (breaststroke, butterfly, freestyle) without a tether. The best-selling swim spa in the range and the right choice if stroke-swim without clipping in is the core requirement.

St Lawrence 20 — dual-temp specialist. 594 × 228 × 137 cm · 5 × 5 HP pumps = 25 HP across two sealed zones (swim end 15 HP, hot-tub end 10 HP). Wins only if the household needs swim-cool (~28 °C) and soak-hot (~38 °C) at the same time with different people in. The swim zone is capped at 15 HP — so the 16 ft is still the better pure-swim spa.

Yes — typically you'll want to clip in for serious stroke work. The 15 HP current is strong for exercise-against-flow, aqua jogging and resistance training, but a 390 cm shell is shorter than a stroke swimmer's lap by design. The swim tether and harness are included as standard so you can hold position while working on breaststroke, front-crawl technique or sustained cardio.

One detail that matters once you're clipped in: you can turn the air out of the water flow. That gives you a smooth, powerful riptide instead of a bubbly washing-machine foam — crucial when your face is in and out of the water and you're trying to breathe without inhaling bubbles. Dial the air back in for casual float-and-play and the fun factor returns.

If clipping in isn't the experience you want, the flagship St Lawrence 16 (500 cm shell · 19 HP routed into the swim end) is designed for stroke swimming without a tether.

Most customers run the St Lawrence 13 at around 35 °C year-round. That's cold enough to climb into for a morning swim without feeling overheated five minutes in, and warm enough that after a longer session the water reads as a proper warm soak rather than a cool pool. The shell holds setpoint regardless of ambient weather — the Balboa heater, closed-cell foam insulation, and IR-lined cabinet do that work.

A note on thermodynamics vs. a hot tub you may have owned: a swim spa is a deep pool of water, so even when you're wading around at the spa end rather than swimming, you're submerged further and for longer than in a standard hot tub. Heat transfer into your body is higher. The rule of thumb most owners settle on: run a swim spa about 1 °C lower than the setpoint you'd use on a hot tub. If your old hot tub sat at 40 °C, run the XSport at 39 °C. If you set a hot tub at 38 °C, the XSport sits happy at 37 °C. Push higher and you'll feel lethargic from overheating before the session is done.

The 13 ft is still an HGV delivery — smaller and lighter than the 16 ft flagship, but not something a domestic pallet truck can handle. Free flatbed delivery to mainland UK is included; you arrange a HIAB or crane lift from the back of the lorry onto your base. We do not book the lift for you — a local operator near you will nearly always be cheaper than one we book from Surrey.

Because swim spas are bespoke per customer, we build the delivery plan with you by phone before you order. Call 01293 824 094 with photos or a sketch of your access route — we work through HIAB reach, base readiness, neighbouring trees, overhead cables and electrical supply together before a deposit goes down. That conversation is worth doing before you order, not after.

Typical HIAB/crane costs for the 13 ft: roughly £300–£600 for a standard lift, cheaper than the 16/20 because the spa is smaller and lighter, more if the reach is long or the garden access is tight. The operator will usually do a site survey or check your property on Google Maps for free. Once on the base, our team fills the spa, walks you through the control pad, and hands over. Electrical connection is separate — see the electrics FAQ.

The St Lawrence 13 is hardwired. There is no 13 A plug-and-play shortcut — three 5 HP pumps (15 HP total) and a 3 kW heater together draw more current than a domestic ring circuit can deliver. One dedicated supply is required:

• 50 A supply (pumps + 3 kW heater) — 230 V

Same spec as the 16 ft flagship — three 5 HP pumps and a 3 kW heater still sit well above what a domestic ring circuit can carry. The supply sits on its own RCD in your consumer unit and terminates at an outside rotary isolator before entering the cabinet. Your electrician runs the armoured cable, fits the isolator, and leaves roughly 5 m of slack outside the spa footprint so our installers can bring the tails into the cabinet on delivery day. None of this kit — RCD, isolator, armoured cable, glands — is supplied with the spa. It's a straightforward job for any competent spark familiar with swim-spa installs, but please have them lined up and the cable run done before delivery. Electrical first-fix sits outside our delivery and installation service.

A 6″ (150 mm) reinforced concrete pad, sized to the full footprint of the spa — 4.0 × 2.3 m minimum. The pad must be reinforced (steel mesh or rebar), over a compacted hardcore subbase, with a properly power-floated finish. An equivalent-strength engineered patio (structural slabs on a rigid mortar bed over a reinforced sub-base, rated for the filled weight) also works — talk to us first if you want to go that route. Do not drop a swim spa onto grass, standard paving slabs, or decking that wasn't engineered for filled weight — we see cracked slab bases fail on swim spas every season.

If you want to run your base plan past us before pouring, send photos to the team and we'll check it.

Two separate layers, both included as standard:

2 years parts & labour — shell, pumps, heater, and control system. If something fails in normal use, we replace the part and fit it, anywhere in the UK. No annual service required to keep cover active — a condition some brands attach to void your warranty if you miss a year.

10 years against water loss through the shell structure — structural protection for the acrylic body.

You can also extend parts & labour by a further 2 years. Swim Spas sit at the top extended-warranty tier — £1,200 (vs £500 Patio Spas, £850 acrylic hot tubs). The extension is stackable — buy it twice and you get four additional years — and can be purchased any time while still under warranty.

Running cost on a ~3,400 L swim-spa shell sits above the £2–£2.50/day figure for a standard hot tub, because you're heating roughly twice the water volume. That said, it's meaningfully less than the 16 ft flagship's ~6,475 L shell. Actual cost depends heavily on setpoint and use pattern — a household holding 35 °C year-round and swimming three mornings a week runs warmer than one that keeps it at 33 °C and dials up only for sessions.

Rough guidance for a typical UK household holding the shell at the 35 °C sweet-spot setpoint year-round: expect monthly costs broadly in the £60–£100 range, weighted toward the upper end in winter. Pairing the spa with a heat pump (Balboa Clim8zone II or similar) typically reduces that meaningfully. Call 01293 824 094 for a model based on your use case and tariff — we run the numbers honestly, not optimistically.

The St Lawrence 13 ships with the Silver Ion Glacier antimicrobial filter set installed. The media is antimicrobial-infused to inhibit bacterial growth on the filter itself. Paired with the Mountain Pure™ UV-C lamp and built-in ozone generator, the result is cleaner water with fewer chemicals.

Replacement schedule: every 4–6 months, or sooner if discoloured. Keeping a second set on rotation is the standard owner trick — swap in a clean set on top-up day, rinse the used set overnight.

Compact gardens, first-time swim-spa buyers, 3-person households. The 13 is the route into proper swim-spa ownership for households that want the category without the flagship's footprint or price. Typical buyers: couples and small families who want to swim for exercise (current-against-flow, aqua jogging, resistance training) without installing a heated pool, people doing low-impact rehab work, households looking for a warmer soak + occasional exercise rather than heavy lap training.

If you want stroke-swim without a tether, see the flagship St Lawrence 16 (500 cm shell, 19 HP into the swim end). If you want dual-temp independence — swim-cool and soak-hot at the same time with two people in — see the St Lawrence 20.

Yes. The whole design target is year-round UK outdoor use: closed-cell foam wrapping the plumbing, an infrared-lined cabinet reflecting radiant heat back into the water, and a hardtop locking cover. A 3 kW Balboa heater holds the shell at setpoint regardless of ambient temperature. The typical use pattern is to hold the water at around 35 °C year-round — cool enough to climb straight into for a morning swim without overheating, warm enough after a session to feel like a hot tub for the evening.

Everything in the What's in the shell list: the spa itself, 1 × 3 kW Balboa heater, 1 × Balboa digital control pad, brown two-piece hardtop cover, full LED mood lighting, Bluetooth pop-up speakers, aromatherapy canister, two cascading waterfalls, swim tether pole (included as standard), installed Silver Ion Glacier filter set, Mountain Pure™ UV + ozone sanitation (UV-C lamp + built-in ozone generator), all manuals, and free flatbed delivery to mainland UK. Optional add-ons: 2 × top-mount cover lifters (one per cover half), chemical starter kit, and the Swim Spa tier extended warranty.

What we do not supply: the HIAB/crane lift (arranged locally — see the delivery FAQ), the electrical first-fix (50 A RCD, isolator, armoured cable, glands — fitted by your electrician before delivery), or the concrete base. These three pieces sit outside our scope and are where most swim-spa delivery friction comes from — plan them early.

Yes — and at this price point it's the right call. Our showroom is at Canada House, Unit 1, Salbrook Road, Redhill, Surrey · RH1 5GL. Ten minutes from Gatwick. Open Monday–Friday 9am–6pm and weekends 10am–4pm. Please call ahead (01293 824 094) for a swim-spa visit so we can have the right spa in the range set up and filled for a proper wet test.