Seasonal aluminum boat dock
 

I am looking to install a 4x30ft seasonal aluminum boat dock. I am considering the following products:

Shoremaster, Hewitt, FWM or a custom docks that has aluminum pipe that is driven several feet into the lake.

My primary concern is stability of the dock for my 24ft boat. Will add whips and cross bracing. Some of the product lines have augers or anchors that can provide some stability since they have mud flat feet that are not driven into the lake (unlike the custom option does).

What are your thoughts?

Appreciate any help you can offer!

One major consideration should be how exposed you are to major boat traffic and/or potential wave action from substantial fetch, etc.

Curious....how do you drive aluminum pipe a couple feet into the lake bottom without it bending? Aluminum pipe cant be that strong?

It sounds like its a permanent dock. If so the ice will crush those aluminum pipes. Since you mentioned custom you may want to get a seasonal lift dock. Can't damage the dock if its out of the water. You may want to check Raise-A-Dock, Wallmark, Center Harbor dock for those. I have a 6X33' dock using galv post with a galv base on each post. Mine just sits on the bottom. Granted I have 2 feet on you for more stability but if you have cross pieces at the end and the 3rd section of the dock it should stabilize the dock. I do not have whips have little boat traffic although when boats come in the waves are in line with my dock and I'm at the mouth of a cove which get the weather. I have a 20' runabout and the dock does not move. I would suggest getting a 6' wide dock, it does make a difference on room. I had a 4' previously.
Also when I got my aluminum dock the installer said not to drill holes in the frame for whips, etc. I can't put whips on my decking since its is not attached. My only choice is to put them on the galv posts.

Dave M

We have FWM, It's a quality product but it does get a little swirly when there is a lot of wave action. I don't think it would be good if you're in a high boat traffic area, JMO. Ours is 4' wide, I agree with others that 6' wide would be much more stable.

Raise-a-dock did our two 40x6’ docks last year. Couldn’t be happier with them. Facing east on Wolfeboro Bay so we get a bit of direct wave action on the weekends. Whips attach directly to the aluminum posts and hold a 27 foot with no noticeable lateral movement to the dock. They feel like permanent docks but easily crank up and down for winter. I imagine a 30x4 would be a bit less stable - agree with Dave M. that 6’ width provides more utility and stability. 2 Adirondacks can sit side by side at the end of the dock with no issues. Good luck with the decision!

4X30 is too small for a 24ft boat IMHO. You really need to go the full 40 feet which is allowed by State plus do a 6 ft wide dock. A 24ft boat is a lot of weight and you might even go for a bigger boat down the line. Do the job correct in the first place. We have used whips, etc, but the screw anchor into the lake bed with a ratchet strap to the dock plus diagonal bracing makes all the difference in the world. If you get a lot of wave/boat action, also use snubbers on the direct lines from the boat cleats to the dock. They take the shock stress off the ropes. I am a true believer in snubbers ! They really work and are worth the investment. I now have an U shaped dock and I use snubbers on aft and bow lines on both sides of the boat. Never get any shocks that rock the dock.

Wolfe-man, do you have links for the post mounted whips. Having trouble finding them.

Thanks Dave M

We just replaced a 40' x 4' wood and pole dock that had trouble with our 23' tri-toon with a lift up U shape from Watermark. The new dock is 6' wide and it make all the difference in the world. You can walk past a kayak or a chair and it is so sturdy. If there is anyway to go 6 foot wide do it.

I also agree with Tummyman about the snubbers, they kept the old dock upright for the past two years. I mounted them to the wooden post of the new dock last week, I'll check them tomorrow.

What is the biggest boat you would recommend for a 4/30 ft dock?

It's the largest dock I can get for my waterfront.

Thanks!

Center Harbor did my 6x30. I had whips on the old wood frame dock, ten feet apart, which I wanted to continue using. So I had them weld in a pair of aluminum plate brackets a bit larger than the whip base footprint, and set a bit down from the top of the frame to accommodate the wood strips to which the deck planks are screwed. The whip bases bolt through the deck and the aluminum plate. I have to remove the bases to take off the deck sections for the winter.

No, Dave, but Raise-A-Dock has a website with contact info. Dennis (the owner) can take care of you. The mounts are quite substantial and well made, in my opinion. I use them with a 27 ft SLX and have had no issues with lateral stability or dock movement, even on busy weekends. The mounts slide over the poles, tighten with a single nut, have a horizontal mounting plate with a 45 degree angled receptacle for the fiberglass whips, maybe 6 inches long.

Aluminum dock, plastic decking, and dock whips
 

My friend has a 60x4 dock at his house. Water is only about 5' at the end. We wanted dock whips for our 25 & 26 ft bowriders, due to the wave action at the dock.

We had 90 degree brackets with gussets made out of aluminum, with one side of the 90 drilled with 4 holes, and the other 90 drilled to match the whip bases.

We drilled through the dock frame and secured the brackets with bolts, nuts, and lock washers. We then drilled up through the brackets for the three mounting bolts for the whip bases.

Result: : our boats ride the wakes and waves, and the dock is rock solid. There is no stress on the decking. This was recommended by the dock manufacturer.

One other thing we did was mark the 6 10' sections. #1 has hinge on one end and connects to #2. The other end of 2 we marked 2->3. #3 marked 2->3 & 3->4, etc. Eliminates problem of slight changes in drilling from one end of a section to other.

Wolfe-man. I have Raise-A-Dock, should have known Dennis would come up something. Question I have is did you have any issues with finding a whip that would mount into the receptacle. Don't know if whips come in same size diameters.

Thanks Dave M

Can't Beat Stainless Steel...
 

In January, I acquired a very sturdy stainless steel pipe, diameter 2.35", wall-thickness .15", and ten feet long. If someone is interested in purchasing it at half-price, send me a PM. It's very heavy, but I can transport it from Florida for next season (about next Ice-Out).

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Dave: I realized I never responded to your question. Dennis offers two whip sizes that fit his mounts, depending on the weight of the boats to be secured. I have 2 sets of the heavier gauge and have had no problems. Sorry if no longer relevant!

The law actually states that if you have under 75’ of frontage you can only have a 4’ x 24’ dock no matter the size of the lake. If less than 1000 acres and 75’ or more for frontage you can have a 6’ x 30’. Larger lakes and 75’ or more frontage gives you the 6’ x 40’ option you mention.

https://www.des.nh.gov/organization/...ents/wb-19.pdf

Fwm
 

We have a 4-ft by 20-ft FWM dock as going longer in our case would require floating the dock. As it is we are 7-ft deep and dropping at the 20-ft length. As with all of these questions its all about money, go as wide and long as the law allows and you can afford.
FWM allows several easy add-ons to their docks which require no drilling such as whips, ladders, built in fenders, lights, etc. I would say as others have to go wider with the dock if possible to provide additional stability.