Table of Contents
The Joie Bay Latch SI 3 in 1 harness to booster seat is forward facing only, uses rigid Lower Anchors and Tethers for Children (LATCH) installation, and costs $239.99. It covers children from 30 pounds in harness mode up to 120 pounds in backless booster mode. The seat has no rear facing mode. It converts through three modes: forward facing harness, high back booster, and backless booster. This Joie Bay Latch SI review collects the limits, measurements, installation rules, and price from Safe in the Seat and Target listings. Prices and ratings were checked in October 2026.
[IMAGE: Joie Bay Latch SI in harness mode, installed forward facing in a vehicle back seat]
Joie Bay Latch SI at a Glance
The Joie Bay Latch SI is a forward facing harness to booster seat from the baby gear brand Joie, and it is the only seat this article covers. This guide does not cover the Joie Saffron SI (a 4 in 1 convertible seat), the Joie Mint Latch (a baseless infant seat), or the Joie Basil (a belt positioning booster). None of the findings here come from hands on testing, because every claim comes from named publishers, Target listings, or buyer feedback.
The table below summarizes the Joie Bay Latch SI specs that matter most to a parent comparing forward facing seats.
| Key fact | Joie Bay Latch SI |
|---|---|
| Seat type | 3 in 1 harness to booster |
| Facing direction | Forward facing only |
| Harness mode weight | 30 to 65 pounds |
| High back booster weight | 40 to 100 pounds |
| Backless booster weight | 50 to 120 pounds |
| Installation | Rigid LATCH connectors |
| Seat weight (harness mode) | 23.7 pounds |
| Price | $239.99 |
| Colors at Target | Shale and Mocha |
The seat has a no rethread headrest and harness system, extendable seat depth, and side impact insert bolsters. The Plus version adds a 7 position footrest.
Related: When to Turn a Car Seat Forward
The Three Modes of the Joie Bay Latch SI and Their Limits
The Joie Bay Latch SI covers three modes, and each mode has its own weight limit, height limit, and head rule. The sources used for this article do not state a minimum age for any mode, so check the Joie manual for age guidance.
Forward Facing Harness Mode
Harness mode holds children from 30 to 65 pounds and from 27 to 49 inches tall. The head rule is that the child’s ears must stay below the top of the headrest. The no rethread headrest and harness system moves the harness height without removing the straps. According to The Car Seat Pros, the harness height runs from 12 inches at the lowest setting to 18.5 inches at the highest.
High Back Booster Mode
High back booster mode holds children from 40 to 100 pounds and up to 57 inches tall. The head rule matches harness mode: the child’s ears must stay below the top of the headrest. In this mode the vehicle seat belt secures the child, and the shoulder belt guide positions the belt. The highest shoulder belt guide setting is 22 inches.
Backless Booster Mode
Backless booster mode holds children from 50 to 120 pounds and from 43 to 60 inches tall. The head rule changes here. The child must have vehicle head support that reaches at least the top of the ears. The backless booster weighs 8.8 pounds, which is 14.9 pounds less than the seat in harness mode.
The table below lists the weight limit, height limit, and head rule for each Joie Bay Latch SI mode.
| Mode | Weight | Height | Head rule |
|---|---|---|---|
| Forward facing harness | 30 to 65 pounds | 27 to 49 inches | Ears below the top of the headrest |
| High back booster | 40 to 100 pounds | Up to 57 inches | Ears below the top of the headrest |
| Backless booster | 50 to 120 pounds | 43 to 60 inches | Vehicle head support to at least the top of the ears |
The weight ranges overlap on purpose. A child between 40 and 65 pounds fits the harness mode and the high back booster mode by weight alone, so the height and head rules in the manual decide which mode applies.
[IMAGE: Joie Bay Latch SI shown in all three modes side by side: harness, high back booster, backless booster]
Joie Bay Latch SI Rigid LATCH Installation and the 40 Pound Rule
The Joie Bay Latch SI rigid LATCH installation is fast, because rigid LATCH connectors attach instantly to the vehicle’s lower anchors. Safe in the Seat and The Car Seat Pros both describe installation as very fast and easy. When the seat is installed with rigid LATCH, it moves less than 1 inch.
The 40 Pound Lower Anchor Limit
The lower anchors carry the seat up to 40 pounds when they are used alone in harness mode. After the child reaches 40 pounds, the installation changes. If the vehicle does not allow the seat belt to be added to the LATCH installation, switch to a seat belt only installation.
Lower Anchors Plus Seat Belt to 65 Pounds
The lower anchors can be used in harness mode until 65 pounds if the seat is installed with both the lower anchors and the seat belt together. Joie allows this combination only if the vehicle also allows it. Read the Child Restraints section of the vehicle owner’s manual before installing the seat with both together. The vehicle manual decides, even though Joie permits the combination.
The table below shows which installation method applies at each child weight in harness mode.
| Child weight in harness mode | Installation method |
|---|---|
| Up to 40 pounds | Lower anchors alone |
| 40 to 65 pounds, vehicle allows both | Lower anchors plus seat belt |
| 40 to 65 pounds, vehicle does not allow both | Seat belt only |
Seat Belt Installation in a Tesla Model 3
The Car Seat Pros reviewer installed the seat with the seat belt in a Tesla Model 3, in both the outboard and center seating positions. The reviewer called the easy install surprising, because seats rarely install easily in that car. This is one reviewer’s report in one vehicle, and it does not predict results in other vehicles.
[IMAGE: close up of the Joie Bay Latch SI rigid LATCH connectors attached to vehicle lower anchors]
Joie Bay Latch SI Size and Measurements
The Joie Bay Latch SI dimensions include a seat width of 18.25 inches, according to Safe in the Seat. The Car Seat Pros measured the external widest point at 19 and 3/8 inches. These two numbers come from different sources and different measurement methods, so this article lists both. No source used here confirms that the seat fits three across, so this article does not claim it.
Here is what each measurement means for a parent:
- Harness height (12 to 18.5 inches): This range shows how far the harness moves from the lowest setting to the highest, and it sets how much room a growing child has.
- Highest shoulder belt guide setting (22 inches): This is the tallest position for the shoulder belt guide in booster mode.
- Width between the side impact insert bolsters (10 inches): This is the space the child’s body occupies between the bolsters.
- Shoulder width (13.5 inches): This is the width of the seat at the shoulders.
- Crotch strap depth (5 to 6 inches): The seat has one crotch strap slot, and the depth changes with the seat pan depth.
- Seat depth (15, 15.5, 16, and 16.5 inches): The extendable seat depth gives four settings, so the seat pan grows with the child’s leg length.
The seat weighs 23.7 pounds in harness mode, and the backless booster weighs 8.8 pounds.
The table below lists every measurement from the sources used for the Joie Bay Latch SI.
| Measurement | Value | Source note |
|---|---|---|
| Seat weight, harness mode | 23.7 pounds | Safe in the Seat |
| Seat weight, backless booster | 8.8 pounds | The Car Seat Pros |
| Seat width | 18.25 inches | Safe in the Seat |
| External widest point | 19 and 3/8 inches | The Car Seat Pros |
| Highest harness height | 18.5 inches | Safe in the Seat |
| Lowest harness height | 12 inches | The Car Seat Pros |
| Highest shoulder belt guide setting | 22 inches | Safe in the Seat |
| Width between side impact insert bolsters | 10 inches | The Car Seat Pros |
| Shoulder width | 13.5 inches | The Car Seat Pros |
| Crotch strap depth | 5 to 6 inches, one slot | The Car Seat Pros |
| Seat depth | 15, 15.5, 16, 16.5 inches | The Car Seat Pros |
Related: Slim Fit Car Seat Complete Guide
Joie Bay Latch SI vs Joie Bay Latch SI Plus
The Joie Bay Latch SI Plus costs $30.00 more than the standard seat and adds a 7 position footrest. The Joie Bay Latch SI Plus has the same limits and measurements as the standard version. The footrest and the higher price are the only known differences.
The table below compares the Joie Bay Latch SI and the Joie Bay Latch SI Plus on price, footrest, limits, and measurements.
| Feature | Joie Bay Latch SI | Joie Bay Latch SI Plus |
|---|---|---|
| Price (checked October 2026) | $239.99 | $269.99 |
| Footrest | Not listed | 7 position footrest |
| Weight and height limits | Same | Same |
| Measurements | Same | Same |
[IMAGE: Joie Bay Latch SI Plus with the 7 position footrest extended]
How the Joie Bay Latch SI Compares With Graco Nautilus and Chicco MyFit
The Joie Bay Latch SI costs $239.99, which is $20.00 more than the Graco Nautilus 2.0 LX at $219.99. The Chicco MyFit ranges from $239.99 to $249.99, so the Joie Bay Latch SI matches the low end of that range and sits $10.00 below the high end. This comparison covers price and the rigid LATCH feature only. The sources used here do not give weight limits or features for the Graco or Chicco seats, so this article states none.
The table below compares the three seats on price, using the figures checked in October 2026.
| Seat | Price |
|---|---|
| Joie Bay Latch SI | $239.99 |
| Graco Nautilus 2.0 LX | $219.99 |
| Chicco MyFit | $239.99 to $249.99 |
The Joie Bay Latch SI vs Graco Nautilus question and the Joie Bay Latch SI vs Chicco MyFit question both include the rigid LATCH difference. The Bay Latch SI uses rigid LATCH connectors that attach instantly to the lower anchors. The sources used here do not state the connector type on the Graco Nautilus 2.0 LX or the Chicco MyFit, so check those manuals for the connector details.
Related: Chicco Fit3x vs Graco SlimFit3 LX comparison
Who the Joie Bay Latch SI Fits Well, and Who Should Look Elsewhere
The Joie Bay Latch SI fits three kinds of families, based on the stated attributes of the seat.
- Families who move the seat between cars: Rigid LATCH connectors attach instantly, and one Target buyer said the seat is easy to move between vehicles.
- Families who want one seat from harness to backless booster: The seat covers 30 pounds in harness mode up to 120 pounds in backless booster mode.
- Families whose vehicle allows the LATCH plus seat belt combination: These families can keep using the lower anchors in harness mode until 65 pounds.
Families who need a rear facing seat should look elsewhere, because the Joie Bay Latch SI is forward facing only and has no rear facing mode. Joie makes a different seat, the Saffron SI, as a 4 in 1 convertible, but that seat is outside the scope of this article.
Joie Bay Latch SI Price and Where to Buy
The Joie Bay Latch SI price is $239.99, and the Joie Bay Latch SI Plus costs $269.99. Both prices were checked in October 2026. Target sells the seat, and it was in stock at the time of checking. Target lists two colors for the seat: Shale and Mocha. Prices change, so check the current price before buying.
Early Target ratings for the Joie Bay Latch SI Target listing are around 4.9 out of 5 stars, based on a small number of early ratings. One verified purchase review from August 17, 2026 rated comfort 4 out of 5, and rated durability, ease of installation, quality, and value 5 out of 5 each. According to one Target buyer, the seat installs in less than 30 seconds and is easy enough for grandparents to install themselves. This is early buyer feedback only, and it is not testing by this site.
According to Safe in the Seat, the seat is a great option if easy installation and extended use are priorities. Safe in the Seat points to the quick install and the tall headrest that gives children room to grow.
[IMAGE: Joie Bay Latch SI Shale and Mocha color options side by side]
Safety Notes Every Parent Should Know
Replace the seat after a moderate or severe crash, according to the crash replacement policy. A seat that has been in a moderate or severe crash is no longer the seat you installed before the crash.
Joie allows a thin towel under the seat as a vehicle seat protector. Use only a thin towel for this purpose.
Follow the seat manual and the vehicle manual for every installation. The LATCH plus seat belt combination is allowed only when both Joie and the vehicle allow it, so read the Child Restraints section of the vehicle owner’s manual first. The sources used for this article do not state a product lifespan, a warranty period, or aircraft approval, so check the manufacturer manual for those details.
Always secure the child in the harness or the vehicle belt according to the head rule for the current mode. In harness mode and high back booster mode, the child’s ears must stay below the top of the headrest. In backless booster mode, the vehicle head support must reach at least the top of the child’s ears.
Related: Do Car Seats Expire?
Final Verdict
The Joie Bay Latch SI 3 in 1 harness to booster seat is a forward facing only seat that covers 30 to 65 pounds in harness mode, 40 to 100 pounds in high back booster mode, and 50 to 120 pounds in backless booster mode. It uses rigid LATCH connectors, allows lower anchor use alone up to 40 pounds, and allows the lower anchors plus the seat belt until 65 pounds only if the vehicle allows it. The seat weighs 23.7 pounds in harness mode and costs $239.99 at Target, with the Joie Bay Latch SI Plus at $269.99 for the added 7 position footrest. Safe in the Seat and early Target buyers both point to the fast installation. Prices and ratings were checked in October 2026, so check the current price before buying.
Frequently Asked Questions
Q.1 Does this seat face only forward?
Yes, the Joie Bay Latch SI is forward facing only. It has no rear facing mode. It converts through three modes: forward facing harness, high back booster, and backless booster.
Q.2 How much weight does harness mode hold?
Harness mode holds 30 to 65 pounds and children from 27 to 49 inches tall. The child’s ears must stay below the top of the headrest.
Q.3 Can the lower anchors and the seat belt work together?
Yes, but only if the vehicle allows it. Joie permits the lower anchors plus the seat belt in harness mode until 65 pounds. Check the Child Restraints section of the vehicle owner’s manual first.
Q.4 When does a child leave harness mode for booster mode?
A child leaves harness mode after passing the harness limits of 65 pounds or 49 inches, or when the ears reach the top of the headrest. High back booster mode starts at 40 pounds, so the manual’s height and head rules decide the timing.
Q.5 What separates the SI from the SI Plus?
The Plus adds a 7 position footrest and costs $30.00 more. The Plus costs $269.99 and the standard seat costs $239.99. Limits and measurements are the same.
Q.6 How heavy is the seat to carry between cars?
The seat weighs 23.7 pounds in harness mode. The backless booster weighs 8.8 pounds, which makes the booster mode lighter to carry.
Q.7 Will the seat fit a small car?
The sources used here do not state whether the seat fits a small car. Safe in the Seat lists the seat width as 18.25 inches, and The Car Seat Pros measured the widest point at 19 and 3/8 inches. Compare those numbers with the back seat space in your vehicle.
Q.8 Does the seat work for a family with two cars?
Yes, according to early Target buyer feedback. One buyer said the seat is easy to move between vehicles. Rigid LATCH connectors attach instantly to the lower anchors, and each vehicle’s manual sets the rules for its own installation.
Aiden is the founder and editor of CarSeatHaven. He researches NHTSA safety standards, AAP guidance, manufacturer manuals, and recall notices, and turns them into plain-language car seat guides for parents.
