Boat length vs dock length

Hi everyone. I'm looking into houses that have docks, in Gig Harbor, WA, which I believe is a very protected harbor.

I anticipate that my future boat will be something around 55-62' LWL.

Many docks are shorter than this. Just considering the boat and dock, and ignoring other factors like whether there is a city ordinance, neighbors, water depth, etc., what do we think of a boat that is longer than the dock it is tied to?

I.e. both the bow and stern lines are going to be reversed compared to how we normally tie up. Not aft of the stern nor forward of the bow.

How much would be acceptable, like in feet or percent? Like if the dock was 48' and the boat was 60' LWL, that would be 6' of overhang (water level) on each end, potentially.

Presume the boat has side gates so boarding is not a factor here.

TIA, Bob.

You can tie up to a real tiny dock depending on a lot of factors. One 5 feet wide...depending....

How protected? Any other points on shore to run lines to? Tidal range? Tie off points on vessel? Can you add pilings or mooring points?......etc.....etc...

Thanks psneeld. See picture for bay. I can't imagine much wave action. I'm talking about across from the marinas. No doubt this is such a hive of boating activity is due to the protection.

The dock rides up and down with the water level so I wouldn't imagine tidal range plays a factor?

Assume high quality boat with many cleat points. Can't add pilings or make the dock longer but could add cleats to the dock as necessary. Assume steel pilings are sturdy and in good shape, can handle a heavy boat. (hmm maybe there is an implied assumption there, that say the driven depth of the piles is adequate for a boat the length of the dock????)

Seems like tying off to shore (or setting an anchor) would be more of an emergency situation with say a windstorm.

I don't think the length of a dock has to equal the length of the boat. Spring lines are what we use to keep the boat from moving forward or aft. One spring forward and one spring aft. The bow and stern lines merely keep the bow and stern from wandering away from the dock. Therefore, the length of the dock can be quite a bit shorter than the boat tied to it.

JustBob said:

Thanks psneeld. See picture for bay. I can't imagine much wave action. I'm talking about across from the marinas. No doubt this is such a hive of boating activity is due to the protection.

The dock rides up and down with the water level so I wouldn't imagine tidal range plays a factor?

Assume high quality boat with many cleat points. Can't add pilings or make the dock longer but could add cleats to the dock as necessary. Assume steel pilings are sturdy and in good shape, can handle a heavy boat. (hmm maybe there is an implied assumption there, that say the driven depth of the piles is adequate for a boat the length of the dock????)

Seems like tying off to shore (or setting an anchor) would be more of an emergency situation with say a windstorm.

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So many variables....but bottom line....hanging 6 or so feet off each end should be doable as long as it isn't encroaching on someone else's property.

Greetings,
Mr. G. beat me to it. Spring lines. If, as you say the dock is solid in the X and Y axis you should be quite able to tie to an appreciably shorter dock (even 50% of boat length IMO) and keep your future boat in a snug and safe position for boarding. IF this will be your home dock, you can lash the heck out of it and leave lines permanently adjusted and in place. Keep in mind this advice is coming from someone (me) who is not allowed to even touch mooring/dock lines...

I would personally run this by an Engineer. A dock behind a house, no matter how long was probably designed with the intent of lighter pleasure craft and was probably built to those specs. A boat you are talking about I think would fall under commercial spec's (we've only had a few warfs come thru the office) and are built heavier and have the piles embedded deeper.

8" diameter, 16 foot centers, 6-8 foot embedment vs. 20" diameter, 8 foot centers, 15 foot embedment. One of those docks will hold a tugboat in a hurricane, the other will come up with a spring tide. . .

Just an example, don't quote my numbers please

cool beans said:

I would personally run this by an Engineer. A dock behind a house, no matter how long was probably designed with the intent of lighter pleasure craft ...

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Right, I totally agree with this. I'll throw this into the mix.

I am 43 LOA without dinghy and my finger is 30 feet, no problems at all

I'd like to reinforce (pun?) the importance of checking that the dock is strong enough to hold the boat. This seems more important than whether the boat overhangs.

Richard

You need to be concerned about liability for personal injury to pedestrians if the boat overhangs the dock, and for damages caused when sticking out into the fairway. Extra-long boats are often placed at long dock ends.

So you guys would say that in the design of the dock, the number of pilings, diameter of pilings, depth driven into specific kind of bottom; this would be formulated for a given max weight boat, perhaps with some consideration for windage?

See picture. This is one of the docks in the area I'm talking about. This dock is roughly 90' long. I doubt it was engineered for this boat? I heard someone was letting the boat owner borrow the dock short term.

Mid-ship cleats (I've two on each side) are a blessing.

We have been in that harbor many times. we choose to anchor as opposed to using the city docks. I think that having an overhang on the private home owners docks like you are noting will not be an issue. Just remember that there are plenty of good wind storms that will be pushing your boat from the south. More than likely onto the dock where most are located in this location.

I would check to see of the pilings are deep enough and the correct diameter for the stresses a large boat will put on them. I would guess there are drawings with the city or whoever gave the permit to build the dock. Maybe even engineers specs with them.

We really enjoy visiting Gig Harbor. It is a nice location to have your own private dock!

markpierce said:

You need to be concerned about liability for personal injury to pedestrians if the boat overhangs the dock, and for damages caused when sticking out into the fairway. Extra-long boats are often placed at long dock ends.

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Thanks Mark, maybe I wasn't clear. It's a private dock, not in the marina. There aren't any pedestrians nor fairways.

We dock our 45 Californian on our 16 foot floating dock with no problem. She rode out Hurricane Matthew just fine tied off to the fixed piling.

Bob, there are some very nice properties on the North side of the harbor with really nice docks. There have always been one or two for sale and I see there are some great ones there now. Every time we leave, we go right past those homes. If I only had $2-3 million to spend on a new house.

We keep our boat in the WSW corner of Gig Harbor. Great place to keep a boat! The only disadvantage is that there is no fuel in the Harbor.

As for the strength of the docks.... Most of the private docks along that stretch were built better than many marinas. As was pointed out, the prevailing wind is from the South, so you will get some exposure there, but in that dock pictured you have a long pier that is providing a lot of bracing from the South.

Still, nothing wrong with having an engineer look at it. The total cost of doing that would be a drop in the bucket. FWIW, the SYC has their Gig Harbor outstation along that same shoreline. Gig Harbor is extremely well protected. Small harbor with steep hill on almost all sides. You will get no wind waves and the whole harbor is a no wake zone.

BTW, that looks like a Thunderbird sailboat tied up along the inside of the dock. They were first designed and built there in Gig Harbor in 1957 I believe.

dhays said:

We keep our boat in the WSW corner of Gig Harbor. Great place to keep a boat! The only disadvantage is that there is no fuel in the Harbor.

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I didn't realize that. Where is the nearest fuel?

I think you may be over thinking this. Put a few lines on the dock and put your boat in gear....if it doesn't seem secure...concrete and chain are cheap enough..... Or just drop a bow and stern anchor if the forecast has windspeed you're not comfortable with. The cost of securing a dock is negligible when considering a waterfront house with a 48' dock and a 60 foot boat.

You might find that a 48' dock is built for a 48' boat and is not strong enough for a 60' boat. A few nights in calm weather is one thing but a strong storm could carry them both away.


Best to insure that the dock can handle the weight and bulk of your boat before committing to anything permanent.

JustBob said:

I didn't realize that. Where is the nearest fuel?

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There used to be a very convenient fuel dock at Pt. Defiance (although a bit of a tight squeeze) but the marina there went bankrupt and so stop selling fuel. Since then (a few years now) I have been getting fuel when I am going by a convenient marina. The closest fuel is South at Narrows marina.

From the GH entrance approximate distances are...

Narrows Marina, 5.4 nm (south of the Narrows Bridge on the east shore by Day Island.)

Tacoma Fuel Dock 7.3 nm (East side of Thea Foss Waterway in Tacoma, generally the best fuel prices around and they donate a share to the Sea Scouts. Discount for over 100 gal I believe as well as discount to TYC members.)

Des Moines Marina 11.3 nm (on the east side of East Passage across from Pt. Robinson on Vashon Island.)

I have also bought fuel at Zittels Marina in the South Sound and in Poulsbo. Kingston can be a convenient fuel stop but they do get busy. Beyond that, I haven't had to buy that much fuel for Kinship yet.

On my sailboat, I would top off the 34 gal fuel tank once a year and call it good.

In post #3 the OP said assume steel pilings in good shape.

If driven in normally, in my experience that would hold a vessel of considerable size and weight.

Once one goes to the trouble and expense of steel pilings, usually smaller vessels were not the target audience.

I am starting to wonder though why someone would go to the trouble and expense unless necessary for the bottom or just didn't want to waste money on a lot of needless dock but did expect a larger vessel.

I agree with others that it's about the strength of the dock and piers more than the length of the dock.

That said, it's reasonable to expect a 60' dock to support a 60' boat, and a 40' dock to support a 40' boat. But I think I'd want to confirm the ability of a 40' dock to hold a 60' boat is unsettle weather.

I agree getting an engineer to check it out, but if the dock shown is similar to the one you're looking at, I doubt there would be an issue. I see at least 5 steel pilings shown that look to be about the same size as the telephone pole size pilings holding up the walkway. The dock shown is 90' long. I've been at marinas that had fewer pilings on 300' docks.
John

It wouldn't take much to sink an extra piling beyond the dock or, as mentioned above, drop a mooring or two at strategic points to secure the vessel safely.

psneeld said:

In post #3 the OP said assume steel pilings in good shape.

If driven in normally, in my experience that would hold a vessel of considerable size and weight.

Once one goes to the trouble and expense of steel pilings, usually smaller vessels were not the target audience.

I am starting to wonder though why someone would go to the trouble and expense unless necessary for the bottom or just didn't want to waste money on a lot of needless dock but did expect a larger vessel.

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Don't know how old the dock is in the picture, but steel pilings have been the only good option in Washington for quite a few years. And even then, DOE is not happy due to leaching from the galvanization. Use of untreated wood piling used to be another option, but only lasts a few years.

most marina's have their boats stern to the dock.......so every 20 feet of dock may be supporting 50+ feet of boat.

There are too many unknowns to give a general answer. Just looking at the dock you posted the photo of, I would see it being fine or I could see major issues in strong winds. Much depends on how connected and how the dock is held in position. The narrow walk to medium dock is the weak point if not properly supported.

However, there are more things you need to be aware of and I have no idea how prevalent they are in that area. However, many areas have limitations on size of docks total, distances from the extended property lines and then on distances the boats must keep from the extended property lines. Again, your area may have none of that but I'd look at all local ordinances relative to docks and docking. In our area there are many different sets of rules.

Make sure your insurance agent is on board with this plan. Underwriters might want to see maintenance schedule.

...seriously people ?!?!!

He doesn't even have the house yet.....

He doesn't have the boat yet......

this is getting comical