Located at the northern end of Great Diamond Island, our 43 slip deep-water marina can accommodate vessels up to 110+ ft. Our private marina is available exclusively for guests at Diamond's Edge Restaurant, the Inn at the Diamond Cove, and all overnight boaters.
Visit the island to explore and take in 193 acres of spectacular natural landscape that inspires outdoor recreation and relaxation. The island is home to Diamond Cove, a small residential community that was a former military base built during America's Gilded age, the luxurious Inn at Diamond Cove, the highly-rated Diamond Edge Restaurant, and the Fort McKinley Museum.
All slip reservations include complimentary water and Wi-Fi, and access to shower and bathroom facilities. Please hail us on VHF channel 09 as you enter the harbor and we'll happily guide you to your slip. All dockage reservations will be processed through Dockwa.
We invite boaters to dock and dine at our newly renovated Diamond's Edge Restaurant featuring fresh, local New England favorites.
If arriving by boat to dine at the restaurant, please book online via Dockwa and make note of your reservation time during checkout.
The marina is in great condition. We are always treated warmly at both the marina and the restaurant. Food is consistently excellent. Dan and Jane
Bad. Dock was not stable, screws proud of boards. Failed even to have the courtesy of responding to a refund request that the dock master encouraged me to make.
Docking at Diamond Cove was great. Chris, the dock master, was always helpful.
The restaurant was great. The Dockwa app we had to use as a private boat owner was cumbersome and confusing. We were told at the restaurant that we could get the dock fee refunded since we ate at the restaurant. When we contacted Dockwa we were very rudely told that they never give free dock space and no one at the restaurant would ever tell a diner that they would. It was an unnecessarily negative interaction. Obviously we had been given incorrect information. It could have been relayed to us much more positively. Very unprofessional. Our meal at the restaurant was lovely
The Marina wasn’t very busy but they were courteous in directing us to the slip
Very friendly and accommodating! Dockwa made it very way to reserve and the marina was great!
Always friendly and helpful
The view was beautiful and we had some help getting into our slip. If you have a dog, it is a walk to get to a grassy area. The marina has shower and bathroom facilities but they are also a considerable walk and when a wedding is taking place, you will not have a private space as the shower is clear glass and out in the open area of the shared bathroom. So while it is an absolutely beautiful location, it’s services that it lists are not easy to access. I highly recommend eating at the Crown Jewel. Amazing food!
Dockmaster Chris is an awesome guy. Super helpful.
Chris was, as usual, helpful and engaging even though we arrived with other boats needing assistance with tie-ups.
Great location and setting , great restaurant service, fantastic dockage service, really nice slip. The only negative was the food for the price was a C-.
Just recently visited to celebrate my mothers 70th birthday. From start to finish - as always - the experience was fantastic. Chris the marina manager started us off with a warm welcome to our slip - and the restaurant manager (who I failed to get the name of but wish I had) and the entire restaurant team went out of their way to ensure we had the exact table and setting on the lawn that we wanted. Everyone bent over backwards to ensure the celebration was perfect. And it was. I’ve written positive reviews before - and know I will continue to do so in the future. To anyone reading this and wondering - whether it’s a short stay, or an extended one - Diamond Cove might just be one of the most welcome sights to any captain and crew. Visit, enjoy, and soak it in. The beauty of the place itself is only eclipsed by the kindness and professionalism of the team that runs it. Cheers. Jameson Smith & Family // M/V Luna II
Dock person was having trouble with his VHF
Easy to book a slip and assistance getting in. Very good experience.
Peaceful and beautiful island. Great marina.
Great marina. Friendly staff!
Dockmaster Chris was excellent!
Great stay and Chris the Dock Master was outstanding. Very accommodating and very customer focused.
The staff at the dock was amazing! Thanks you.
We only docked at the marina. There was a wedding at the Edge. Chris at the marina gets 5 stars though! :)
Very nice service! Easy walk to restaurants
Our party was met at the dock by Chris and his staff, smiling and ready to catch lines! The slip space was conveniently located close the ramp. We had a great stay.
The dock staff was extremely helpful, informative, and professional. We will return as it was a true pleasure to stay here.
Chris the dock master was terrific. It was very busy with boats arriving for dinner and he took the time to make sure we were properly tied up, had shore power, etc.
Great marina for a visit!!
Perfect. Nice dinner and great dock help.
The dock master was great, very helpful
the dockmaster was excellent, we had a nice comfortable slip. The bathroom and cold shower was .25 miles away, making it a Half Mile round trip . There was no hot water in the bathhouse. The Island is private, so there were no trails or roads to walk on, the Inn had a pool, but it was for guests of the Inn only. The WIFI was down on the docks, and there was no cell service, but I did not expect that anyway. The restaurant was excellent, well worth the price, and service was very good.
The dockmaster, Chris, was terrific! The only reason this didn't get a 5 star rating was that our dining experience at Diamond's Edge was disappointing. Nice trails for walking.
Great marina. Chris is a super helpful and friendly dockmaster. Beautiful island to explore
Easily accessible and nicely maintained. Great spot on Casco Bay.
Nice Marina, and dock master.
Excellent service. This survey is ridiculous to require a longer answer.
Great experience. Worked seamlessly.
Marina was a good experience. Spacious slip well attended by dock staff, easy communication
Nice marina and dock master was very helpful. We did have to wait a few minutes to get in - but the dock master took care of it promptly.
Great help, easy access, nice experience
Aiden was very nice and capable.
Great place for lunch, easy to dock, Food, and service at the Diamound's Edge restaurant. The docking manager/dock hand is accommodating and pleasant. Tom Santospago
Easy in easy out with great help from friendly dock staff
Lovely & well run marina as always!
Friendly dock master. Great help. Quite harbor. Added bonus poor cell service so you can really not be bothered.
Wonderful place and so pretty. It would be a 5 star if they had wi-fi. Cell service is almost zero.
Super helpful and friendly staff
Great experience. Was ready to receive us as we approached and helped tie up. Marina is a little tight but plenty of room.
Nice small marina. Super helpful dock hands
Dockmaster helpful and professional
Fabulous place, super friendly!
Friendly staff and calm marina
Nice dock facilities, very helpful staff.
Great dinner, great service both at restaurant and dock staff.
Very helpful staff.
The dock person was very friendly and helpful.
Nice sheltered cove. The dock master was experienced, knowledgeable and very helpful!
Great staff. Accommodating and very welcoming.
Dockmaster was incredibly helpful, professional and courteous. Glad we stopped and will return!
Excellent service at a the Marina!
easy to work with every time I have been there there were open slips and very easy to reserve the dockmaster was exceptional as well
We visit Diamonds Edge often and have never had a problem. Works like it’s supposed too👍
Easy in and out slips
Great service and very friendly dock manager. Would highly recommend a stop in.
Excellent communication. Welcomed us at the slip.
for the price you don't get very much
The facility, the people, the beauty - all outstanding. Couldn't ask for anything better. Chris was outstanding and sooo helpful. Goes above and beyond to accommodate you....
Nice place and a great dinner.
great people, the island is beautiful, views amazing and its so peaceful .The Ferry or water taxi options are great for Portland.
Great marina and location for visiting GDI. Chris the manager and all other staff were helpful and a pleasure to talk with. Can’t wait to go back.
Chris, the Dockmaster was very helpful and friendly. We ate at the Diamond's Edge Restaurant and the food and drinks were excellent. Very positive experience.
Great service at the marina and great service at the restaurant. The drinks were tasteless and the food was 3 stars at best. Next time we will bring food and grill on the boat.....
Actually, 4.5 stars. Lovely, lovely spot on this earth, like no other. Not 5 only because not well set up for the cruiser crowd....no W/D, showers a bit of a hike. Dockmaster Chris quite helpful and friendly, restaurant 4.7. Will definitely be back.
Diamond's Edge is an incredible stop. The island itself combined with the hospitality makes it a real gem and a stop we like to make at least once every year.
Three friends and I dined at Diamond's Edge this past Friday night. The dockmaster was exceptionally helpful and friendly. The dining experience - on the lawn - was fantastic from start to finish. Highly recommend Diamond's Edge to all my friends.
Chris on the dock was the best and more than helpful. Restaurant soo much better than last time which was before Covid. The walking map very helpful in understanding where the permitted places were to walk. Street names would be helpful on the map. The lady at the inn fixing our bagel breakfast could not have been nicer. She made our morning. Good job to all.
As always, this is one of the most pleasant marinas to pull into. They're always waiting for you to arrive and ready to help you dock. And it's such a beautiful location with great food and fun beaches! Update: A year later, another visit, and another great experience. The marina manager always makes the process so easy, and it is such a great location.
We love coming in to Diamond Island. It is one of our favorite trips. Chris, the Dockmaster, is always accommodating. It is always a great dining experience at the Inn restaurant, and enjoy the amenities at the hotel.
Amazing, secluded little spot. Food and drinks at Diamonds Edge restaurant are phenomenal. The dock master Chris is friendly, helpful and accommodating. The inn is beautiful and we’ll probably stay a night or two next year to break up a long boat vacation. My only complaint is there is limited hot water if someone is in both the men’s and women’s showers. You might end up running out so best to put some time between showers.
Great small marina with two good restaurants a short walk away. Note-No WIFI or cell service. Chris Johnson, the dock manager, is the best!!
Chris and his team were very helpful/responsive in getting us situated on the island. Thanks for a great experience.
This location is absolutely beautiful. Small protected cove, very close to Portland. The amenities are limited...no wifi, spotty cell service, bathrooms are quite a long walk. The residents of the island do not want marina guests to walk around. You are required to request a golf cart ride up to the Inn to use the pool. Chris is a very pleasant and customer service oriented manager. He does a great job! Also, skip the Diamond's Edge restaurant and eat at Crown Jewel instead where the food outstanding!
Wonderful help on and off the dock.
Chris and John are excellent at their craft. Very helpful. Really enjoyed the comings and goings of the ferry.
Diamond’s Edge Marina was amazing! Dockwa calculating the wrong dockage fee was our only issue.
The dock manager was very helpful and friendly. They are a little short handed, but everything seemed to get done and I got all the help I needed.
The dock master was rude and offensive. He asked us to tip the dock hand which we already had done. He then came to our table to confirmation our reservation which we did online. He again asked us to tip the dock hand. When we returned to our boat, he asked us again about tipping the dock hand. He was pleasant enough, but was extremely rude and intrusive by constantly chasing us down for the fee for stopping at the dock and tipping the dock hand. Unfortunately, I will not return there because of him. I guess the $250 lunch isn’t good enough.