Mariners Grand Slam Camps

Frequently Asked Questions

How are safety issues handled at camp?
Camper safety is our utmost priority. We have multiple certified teachers on staff at each site who are fully trained in first aid/CPR, concussion protocol, and sudden cardia arrest in accordance with all state laws. Our entire staff receives training in these areas as well. All matters related to infectious illnesses are dealt with according to all state and local guidelines in place at the time camp is held.

Why Mariners Grand Slam Camps?
The Seattle Mariners Grand Slam Camps are real baseball and softball camps. You can count on top quality and personalized instruction while having a blast. After all, it is a game and should be fun - lots of fun! Compare us to other camps. You will find that unlike other camps, we are offer a unique blend of high quality coaching for all skill levels.

Compare us to other camps. You will find that unlike other camps, we are a unique blend of high quality coaching of all skill levels. We provide a staff that loves the game, knows the game and loves working with kids. Some camps out there take things too seriously, they just don't have any fun. We do! Our unique, balanced approach has been working for us since 1993 and ensures a great experience for all.

Our focus has been on providing a well-planned camp experience that is like no other and is coordinated and coached by teachers and college ball players who have played high-level baseball and softball. Each camp session is well organized, efficient, built upon sound educational principals; using Positive Coaching Alliance methods and is always spiced with our total love for the game.

The Seattle Mariners, while a major league club pursuing the highest level of achievement on the field, understand they are a key community member. Our camp plans to continue inspiring young campers to be ballplayers through our commitment to encouraging the positive culture of the sport; namely hustle, sportsmanship, looking sharp, respect, class, history and enthusiasm. We are confident that Mariners Grand Slam Camp is second to none!

Travel Ball Player or All-Star? This camp is for you too!
Many of our participants last year were players on travel ball teams or were part of their league's All-Stars. We fully recognize that players with upcoming weekend tournaments may want to rest their arms and will respect those wishes. Know that our instructors are experts in the game (former pros, high school and college coaches, current college players) who have played at a high level and can stretch the skill development of all levels of players. We address not just physical skills but proper mental approach. We teach all players in a manner that improves their game.

How much does it cost for camp? Do you offer any discounts?
$155 for the Complete Camp or the Skills Camp. $295 for the Complete Extended-Day and the Complete & Skills Camp Bundle.

We offer several potential discounts:

We offer several potential discounts either $10, $15 or $20 off:

Qualify for one of the below = $10 discount
Qualify for two of the below = $15 discount
Qualify for all 3 of the below = $20 discount.

  1. Returning campers discount
  2. Siblings who attend the same camp and location discount
  3. Military / First Responder Family discount

The discount codes below can be entered at the final payment page.

  • If you are eligible for one of the above, enter discount code: 24SEACAMPS10OFF
  • If you are eligible for two of the above, enter discount code: 24SEACAMPS15OFF
  • If you are eligible for three of the above, enter discount code: 24SEACAMPS20OFF

Know that the price of signing up for the Complete & Skills Camp Bundle reflects a discount ($295) from the cost of both camps combined. The bundle also includes supervision each day during the lunch break between sessions at no additional cost. Discounts are taken automatically when discount codes are input at the final payment page of the online application.

What should a camper wear to camp?
We ask that the campers dress for camp as they would for practice. Some examples include: tee shirt/sweatshirt, baseball pants or sweats, athletic shoes or cleats (no sandals/flip flops), athletic cup, team uniform or practice gear are also worn by many campers. If the weather is very hot some campers will wear shorts on those days. Make sure to bring a jacket for cool or rainy days. Please have campers name marked on all valuable items.

Do you have an Inclement Weather Policy?
Regardless of weather, camp will never be canceled, even if we encounter rain. We have rain-specific activities that continue to enhance the learning and fun. Rainy days happen here in the Northwest, but are typically light and pleasant. Let's play ball!

What should each camper bring with them to camp?

Make sure camper's name is clearly marked on all gear!

All campers please bring snack and plenty to drink (we break for snacks at 11:00 in the AM and 2:00 in the PM)

Bring lunch if you are attending the Complete Extended-Day Camp or Complete & Skills Camp Bundle.

Baseball/Softball glove

Bat to Skills camps (if you have a bat, you may bring to the complete camp too)

For Catchers camp we do have gear but you may bring your own if you like.

Any other ball gear of your own you would like to use like helmets, etc.


My daughter loves baseball, does she have to attend the softball camp?
She may choose either the baseball or softball camp. Both are great. As she gets older she will naturally transition into fastpitch softball which is now highly competitive and very fun. UW Husky pitching coach, Lance Glasoe, designed the curriculum for our softball camp. Your daughter will receive excellent instruction in a high energy, fun, instructional atmosphere. If she can't attend a softball camp, many girls have attended our baseball camps and loved it! The base skills are the same except for pitching and slap hitting. Given our camps are coordinated by certified teachers, you can be assured that your daughter will feel comfortable and have a great time. Some girls have signed up with a friend to make them feel more at ease.

Can I reserve a spot via phone or email?
No. All openings are secured on a first come, first served basis. A completed application and full payment must be received via our online checkout.

How do we get signed up?
Simple. Just go to and select the "Register Now" button.

What kind of staff do you assemble?
Each camp location is lead by at least one certified teacher - and typically more - to ensure safety, fair play, and proper structure. Most of our coaches have played college baseball or coached at the high school level. All our staff are trained in how to properly work with player in the 6-12 age range.

My child wants to attend both the Complete and Baseball Skills camp. Is this OK?
Yes. In fact, this is quite common. The two camps are quite different in structure and complement each other nicely. We have our Complete and Baseball/Softball Skills Camp Bundle for those campers.

My child is attending both camps (Extended Day and Bundle). Is there supervision provided from during this break?
Yes. Direct supervision and activities are provided at no additional cost for this lunch time each day.

Your Baseball and Softball Complete camp is for kids in 1st through 6th Grade (2023-24 school year). My child is in kindergarten. Can he/she attend too?
We are hesitant because inexperienced campers find it to be too overwhelming and still struggle with thrown or batted balls. If your kindergartner has experience playing, then it should work out just fine for the Morning Complete Camp only (not Extended-Day). But please, keep in mind, it is a long session and can sometimes be very warm or cold. In the end, the discretion is yours.

I see there's quite an age range. Are the kids grouped together or are they separated?
Kids are predominantly grouped by skill and age. Common sense and the expertise of our coaches lend itself to appropriate grouping of the kids. Safety and the ability to learn while having fun are the guidelines. Our coaches are very attentive on the first day and throughout camp to appropriate grouping of the campers.

Can I get a receipt?
Please use your credit card statement and/or printed confirmation email as your receipt.

How should we dress for camp and what should we bring?
Dress athletically, ready to play ball! Be prepared for any weather. Bring your glove, cap, a snack (or full lunch if with us all day), plenty of water and sunscreen. You may bring your bat, helmet and other gear too. With anything of value, be sure your name is clearly marked. For catcher camp, we do provide catcher's gear, but you may bring your own.

Do you offer a military/first responder discount?
Yes, if you have a family member who is active or retired in the military or defense department or first responder! Each family member receives $10 off the application fee and this can be used with other discounts (sibling & returner). The discount codes are found on this page above following the question “How much does it cost for camp? Do you offer any discounts?” Discount codes can be entered at the final payment page.

We live in a time when kids are pushed to excel in activities younger than ever before. The key with any activity, baseball or fastpitch softball in this case, is to build an enjoyment of the game, with technical training at a pace that matches the natural human developmental process. Teaching fundamentals is terrific, but intense training too early has no benefit. Those that love the game will play and practice it more, ultimately reaching their potential, whether they are limited in ability or the most talented. Kids without love of the game will pull away and sadly, stop playing. Our philosophy is to ensure a true passion is built within every player, while at the same time teaching proper fundamentals and learning the game. We teach fundamentals, lots of game situational concepts and boy do we bring the fun!

Cancellation Policy
We ask for cancellation notice a full two weeks before the first day of your selected camp to receive a full refund. We handle all last-minute emergencies on a case-by-case basis.