Thursday Pools Rectangle Fiberglass Pool Shell Options by Size, Depth, and Features

Rectangle fiberglass pools come in more variety than many buyers expect. The shape is consistent, with clean lines, straight walls, and sharp corners, but size, depth, and built-in features vary by model. The right shell depends on your yard size, how you plan to swim, and whether you want lounging space, sport depth, a beach entry, a spa, or a deep end.

Compact Rectangle Fiberglass Pool Shells

These models are part of Thursday Pools’ Plunge Pool Series, built for smaller backyards, courtyard spaces, and homeowners who want a genuine pool experience in a compact footprint. All three share the same 8’4″ x 16′ rectangle shell at 4’8″ flat-bottom depth. Sea Turtle offers a slightly larger 9.5′ x 19.5′ rectangle shell. The smallest sizes of Aspen and Goliath are also part of the Plunge Pool Series with 12’ x 25’ rectangle shells.

The Drift

The Drift is designed for lounging as much as swimming. Its full-length wraparound bench supports social gatherings, cool evening dips, and extended relaxation.

• A full-length wraparound bench creates a comfortable seating zone without giving up the swim area.
• Built-in steps and a non-skid surface throughout provide safe, easy entry and exit for all ages.

The Nest

The Nest maximizes open water in the smallest Thursday Pools rectangle shell. Full-width entry steps and a clean, unobstructed swim area make it the most activity-forward of the three 8’4” x 16’ options.

• Full-width entry steps provide a wide, easy point of entry.
• The open interior layout keeps the swim area clear for exercise and play.

The Nook

The Nook brings minimalist design and integrated seating to the compact rectangle format. It works well as a private courtyard pool or as a compact water feature beside a patio, outdoor kitchen, or seating area.

• Integrated wraparound bench seating lines both sides of the pool.
• Built-in steps and a non-skid flat-bottom surface throughout.

Sea Turtle

Sea Turtle steps up to a 9.5′ x 19.5′ rectangle shell at 4’6″ flat-bottom depth. It suits smaller yards that need a bit more swim room than the 8’4″ x 16′ models provide, and adds a swim-jet-ready design for light exercise.

• A 4’6” flat-bottom depth throughout allows comfortable standing, socializing, and light activity.
• Wraparound benches flank the entry steps, creating a relaxed conversation area.
• Swim-jet-system-ready design makes it easy to add a resistance swim system like Badu®.

Sport and Social Rectangle Fiberglass Pool Shells

These models share a flat-bottom sport-depth design, making them well-suited for water games, family play, and active use. All maintain a consistent standing depth of 4’6″ to 4’8″ throughout the pool.

Lil Bob

Lil Bob is built around a 13.5′ x 27.5′ flat-bottom shell at 4’6″ throughout. It’s a strong choice for families who want a sport-focused pool that keeps kids and adults in the game together.

• Full-width ergonomic steps make it easy for everyone to enter and exit the pool.
• A standing-depth, flat-bottom design makes Lil Bob a great size for water volleyball.
• Two facing benches, each 12 feet long and 18 inches deep, run down both sides of the pool, leaving a clear open swim area in the center.

Lil Bob LX

Lil Bob LX extends the Bob family formula to a 13.5′ x 35.5′ shell with a 4’6” sport depth, adding a tanning ledge and wading area while keeping the flat-bottom sport depth.

• A tanning ledge accommodates two lounger chairs while leaving room to enter and exit the pool.
• A wading area just past the tanning ledge gives younger swimmers a comfortable shallow zone.
• Generous wraparound benches run along both sides of the open swim area.

Big Bob

Big Bob is the largest pool in the Bob family. It’s a 16′ x 40′ flat-bottom rectangle with a uniform 4’6″ depth throughout. It gives families who love the Bob design more of everything: more bench space, more open water, and more room for games and laps.

• Extra-long wraparound benches, 12 feet long and 18 inches deep, run down both sides of the pool.
• Wide walk-in steps make getting in and out easy for swimmers of every age.
• The open 16′ x 40′ swim and play area accommodates lap swimming, water volleyball, basketball, and active family games.

Spirit

Spirit runs 13.5′ x 40′ at a flat-bottom depth of 4’6″, giving it one of the longest open swim lanes in the sport-depth rectangle category. Spirit is best for homeowners who want lap-friendly length while keeping the entire pool at a comfortable standing depth.

• The court-sized flat-bottom design gives swimmers and players plenty of room.
• Extended bench seating and full-length steps at both ends of the pool create multiple entry and social zones.

Mack Daddy

The Mack Daddy is a 16′ x 36′ flat-bottom rectangle at 4’8″ depth that packs four distinct pool zones into one shell. It’s the only rectangle design in the Thursday Pools lineup with a built-in integrated spa.

• A built-in tanning ledge accommodates two loungers with room to enter and exit the pool.
• An integrated spa with a tranquil spillway adds a dedicated relaxation zone.
• Wraparound bench seating adds a third area for sitting and soaking.
• A uniform 4’8″ flat-bottom depth keeps the swim lane accessible for games, exercise, and active family use.

Magnate

The Magnate shares the 16′ x 36′ flat-bottom shell at 4’8″ depth with the Mack Daddy but trades the spa for a more streamlined layout built around an oversized sun shelf.

• A built-in sun shelf accommodates tanning in lounger chairs.
• Double-entry wraparound benches and step-in stairs form two conversation areas and two points of entry.
• A wide-open swim lane runs the length of the pool for laps, exercise, and active use.

Deep and Feature-Rich Rectangle Fiberglass Pool Shells

These models offer deeper depth profiles, tanning ledges, swim-out benches, courtesy ledges, and beach entries. They suit buyers who want more traditional swimming depth alongside built-in comfort features.

Aspen

The Aspen is one of Thursday Pools’ most popular rectangle designs, available in five sizes ranging from 12′ x 25′ to 16′ x 40′. It pairs a signature 12-inch tanning ledge with a deep-end design and multiple built-in comfort zones.

• A 12-inch deep tanning ledge comfortably fits two lounger chairs with room to enter and exit the pool.
• Curved steps stretch across the width of the pool for wide, easy entry.
• An extended bench near the steps gives swimmers a place to rest and socialize.
• Deep-end swim-outs offer a second exit point and a comfortable perch in the deep end.
• The wide-open swim lane runs down the center of the pool for laps and active use.

Grace Beach Entry

Grace Beach Entry brings a zero-entry, beach-style entrance to a rectangle shell, giving swimmers, children, and pets a gradual way into the water. The patented design (US 10,472,839) is available in three sizes from 14′ x 36′ to 16′ x 40′.

• A gently sloping beach entry makes getting in and out easy for swimmers and pets alike, and fits two lounger chairs in the shallow zone.
• A wading area just past the entry works well for young children and doubles as a cool-off zone.
• An extended bench runs along the pool for relaxing and socializing.
• Dual deep-end swim-outs provide an additional exit point and resting zone.
• An open swim area anchors the middle of the pool for laps and active use.

Goliath

The Goliath is available in six sizes from 12′ x 25′ to 16′ x 41′, with depth profiles ranging from 5’4″ to 6’8″. It suits buyers who want a serious deep-end swim experience alongside strong entertaining capacity.

• A wide-open swim lane runs down the center of the pool for laps and floating.
• Bench seating flanks the entry steps for a comfortable social zone.
• Two sets of curved steps in the shallow end and swim-out ledges in the deep end provide multiple entry and exit points.

Monolith

Monolith is Thursday Pools’ deepest rectangle pool model. Its 16′ x 40′ shell reaches 8’6″ at the deep end and includes a flat-bottom shallow end for play. Because diving safety depends on pool dimensions, equipment, installation, and applicable standards, homeowners should consult their dealer, equipment manufacturer, and local requirements before considering any diving or slide use.

• The 8’6″ deep end qualifies the Monolith as a Type 1 diving pool under applicable standards.
• A large flat-bottomed shallow end leaves room for pool games and active play.
• Angled steps make it easy and safe to enter and exit.
• A shallow-end bench and dual deep-end benches give swimmers options for resting and socializing at both ends of the pool.

Thursday Pools strongly recommends that diving boards and slides not be installed or used with its pools because of the inherent dangers associated with diving boards and slides in residential pools, including severe injury or death.

Thursday Pools does not manufacture or sell diving boards or slides.

If a homeowner chooses to install or use a diving board or slide despite this warning, the homeowner assumes all related risks and is responsible for confirming that the pool, equipment, installation, and use comply with manufacturer specifications, applicable ANSI/NSPI, ANSI/APSP, ANSI/APSP/ICC standards, and all applicable laws, rules, and regulations.

Find the Fiberglass Pool That Fits Your Yard and Lifestyle

Not sure which rectangle fiberglass pool shell is right for your yard? Use the Pool Selector Tool to compare rectangle fiberglass pool shells by yard size, intended use, and desired features. For site-specific guidance, contact a Thursday Pools dealer near you for a yard evaluation and installation estimate.

Frequently Asked Questions About Rectangle Fiberglass Pool Shells

What is a fiberglass pool shell?

A fiberglass pool shell is a pre-molded, single-piece pool structure manufactured from layers of fiberglass and resin in a controlled factory environment. The finished shell is transported to your property, set into the excavated hole, connected to plumbing, and backfilled. Because it arrives as a complete unit, installation is significantly faster than concrete and avoids the on-site curing and finishing work associated with other pool types.

What rectangle fiberglass pool shells does Thursday Pools offer?

Thursday Pools offers a wide range of rectangle fiberglass pool shell designs, including The Drift, The Nest, The Nook, Sea Turtle, Lil Bob, Lil Bob LX, Big Bob, Spirit, Mack Daddy, Magnate, Aspen, Grace Beach Entry, Goliath, and Monolith.

What is the best rectangle fiberglass pool for lap swimming?

Any rectangle pool with a long, unobstructed swim lane works well for lap swimming, but the right choice depends on how seriously you swim. Spirit (13.5′ x 40′), Big Bob (16′ x 40′), Aspen (up to 16′ x 40′), Goliath (up to 16′ x 41′), and Monolith (16′ x 40′) all give you meaningful length. If you want a deep-water feel for laps, Aspen, Goliath, and Monolith offer deeper profiles. If standing depth and open swim area matter more, Spirit and Big Bob are the flat-bottom options at that length.

What is the best rectangle fiberglass pool shell for families with young children?

Flat-bottom pools at 4’6″ to 4’8″ depth are often a strong choice for active family use because the depth stays consistent from end to end. Depending on swimmer height, they may be easier to use for games, supervision, and shared play than pools with a steep depth transition.

What is the difference between flat-bottom and deep-end rectangle fiberglass pools?

Flat-bottom pools hold a consistent standing depth from end to end, typically 4’6″ to 4’8″. That uniform depth suits water sports, family play, water aerobics, and any activity where swimmers of varying heights need to touch the bottom. Deep-end pools slope from a shallow entry zone to a deeper swim area, usually 5’1″ to 6’8″ depending on the model. Deep-end designs offer more vertical swim space and a more traditional pool feel. Monolith is the deepest rectangle pool shell option, reaching 8’6”.

Can I get a small rectangle fiberglass pool shell?

Yes. Thursday Pools’ smallest rectangle shells include The Drift, The Nest, and The Nook, all measuring 8’4″ x 16′ at 4’8″ flat-bottom depth. Sea Turtle steps up to 9.5′ x 19.5′. Buyers who want a larger compact rectangle shell can also compare the smallest Aspen and Goliath sizes at 12′ x 25′.

What features do rectangle fiberglass pool shells come with?

Depending on the model, Thursday Pools ‘ rectangular fiberglass pool shells may include tanning ledges, integrated spas, wading areas, wraparound bench seating, swim-out benches, courtesy ledges, beach entry zones, and auto-cover readiness.

How long does a fiberglass pool shell last?

Fiberglass pool shells are known for long service life when properly installed and maintained. The gel coat surface is designed to resist algae and mineral buildup, and the single-piece construction avoids liner seams and concrete replastering. With proper water chemistry and routine care, a quality fiberglass pool shell can last for decades. Consult your Thursday Pools dealer and review the warranty for specific coverage details.