What’s the minimum depth you would sail in?

[Letterkenny]

There’s a part of the San Diego bay here they gets shallow but is a very nice place to sail. There’s not a lot of boats (partly due to the depth) and gets good wind as it’s not blocked by Point Loma. I’ve sailed there quite a bit without issue but know of a couple shallow spots. The depth charts put the shallowest point as 9’ (with the exceptions of a couple small 5’ and 7’ areas) at low tide which on the current boat means a bit over 3’ under the keel. One additional comfort is that it’s a muddy bottom so if you do ground the boat, it shouldn’t be too much of a consequence. Depth finder never has had it below 12’ in actual practice but curious know what is the minimum depth that other sailors are willing to travel?

[Tillsbury]

Depends on where you're used to sailing. I learnt on the east coast of the UK, where three feet under the keel counts as very deep water and no concerns. We would touch the bottom two or three times a weekend because our 28 footer had almost 6 feet of keel.

Around here they get iffy when there's less than 5 metres, I don't get it

[BillKny]

So many sailing newbies want nice simple answers that are always true, and there are none. The answer is always “It Depends”

It depends on things like:

• Is the tide rising, or falling?
• Is the bottom mud, sand or rock?
• The level of detail and reliability of available charts.
• Your level of local knowledge.
• Is the bottom flat, sloping, or rapidly changing?
• How big is your boat?
• How we’ll does your boat take to ground? Is it fragile in keel or rudder?
• Is the local area subject to strong currents that can rearrange soft bottoms?
• Experience level of captain and crew.
• How fast do you sail?
• How remote is the area from help if needed?
• Do you have the skills and tools to help yourself if your ground?
  
• What’s the weather now? Is it changing?
  
• Your level of risk tolerance.
  

There have been times we have sailed miles with less than 30 cm under our 2 m keel. And other times and places where I sweated bullets with a meter to spare.

It Depends

[rslifkin]

Originally Posted by BillKny

So many sailing newbies want nice simple answers that are always true, and there are none. The answer is always “It Depends”

It depends on things like:

• Is the tide rising, or falling?
• Is the bottom mud, sand or rock?
• The level of detail and reliability of available charts.
• Your level of local knowledge.
• Is the bottom flat, sloping, or rapidly changing?
• How big is your boat?
• How we’ll does your boat take to ground? Is it fragile in keel or rudder?
• Is the local area subject to strong currents that can rearrange soft bottoms?
• Experience level of captain and crew.
• How fast do you sail?
• How remote is the area from help if needed?
• Do you have the skills and tools to help yourself if your ground?
• What’s the weather now? Is it changing?
• Your level of risk tolerance.

There have been times we have sailed miles with less than 30 cm under our 2 m keel. And other times and places where I sweated bullets with a meter to spare.

It Depends

This is it. It varies a lot based on the situation. In any boat (power or sail), I generally figure that if I'm not needing to get into a specific shallow place, I should have at least 5 feet under me, preferably 10. Basically, the goal is to always keep yourself in a situation where you're reasonably convinced that you won't hit anything that would cause damage and won't get yourself stuck.

With a sailboat, if I know the bottom is soft and there's nothing sticking up to hit (such as a shallow but maintained channel), I'll get within a few inches if I need to, provided the weather is calm enough.

My own powerboat has 3'8" draft with full tanks in fresh water, I generally round up to 4' for any extra load plus a little bit of boat movement. With that, I don't particularly like seeing less than 10 feet total depth. If I'm going in somewhere shallow, the depth alarm trips at 3 feet of clearance (about 6.7 feet of water). If I don't know the bottom, that's time to bail out. If I'm pretty convinced it's a clean bottom, I'll push it to 6 feet before bailing out, and occasionally, if I know the bottom well in that area (or am in clear enough water to see the bottom) and the bottom is soft and weather is calm, I'll push it to 5 feet before I put the engines in reverse and get out of there.

[Group9]

It depends. When I lived in Annapolis, the bottom was mostly soft mud, and would usually slow you down for a while before it stopped you, giving you plenty of time to veer back to deeper water. Six inches of clearance was plenty for me.

Where I live now, the bottom is hard sand, and when you hit, it's like the brakes got thrown on in your car. When I get less that two feet under my keel, I start paying attention, When it gets to six inches, I start looking to turn around!

[denverd0n]

Like BillKny said, it depends. And like Tillsbury said, one of the things it depends on is what you are used to. Here on the west coast of Florida there is a lot of shallow water. So I generally figure that if I've got more than a foot under my keel, I'm doing just fine. You just get used to keeping a very close eye on how deep the water is that you're in, and what is up ahead.

[Stewie12]

If you sail in the Bahamas you will soon get used to knowing the dept of water by its colour. To do this you need good light. I have spent all day crossing the Turks and Caicos bank in about 11 feet of water whilst drawing 6.6 and also looking for coral heads. There is very little tidal difference there and you get used it.

[GreenWave]

I sail in Galveston Bay, Texas. The bay is soft mud bottom, very murky brown water so cannot see the bottom and depths are 8-10 feet. Nice thing about the bay is that the depth is very constant and there is less than 2 feet tidal change. Some sailors would not be comfrotable with this, but I am fine.



So where I sail I have 3-5 feet under my keel. Hardest part is getting out the channel leaving my marina where I often encounter less than a foot at low tide.

[sail sfbay]

Agree with the posts above........I will add, make sure you know the depth at low tide of the area you plan to sail BEFORE you sail in that area, have a depth gauge that measures clearance under the keel, have a charplotter that shows depth at low tide. Consider sonar that sees the contour of the bottom and type of bottom. Where I sail, generally in the San Francisco Bay, the average depth is about the same as that of a big swimming pool — an average of 14 feet deep, according to The Bay Institute with an average of 43 feet in the center. We generally sail in depths with 8+ feet clearance under the keel and stay away from shallow areas because we can.

[AJ_n_Audrey]

+1 what BillKny said. I'm very comfortable with 3 feet under the keel on the Bahama Bank if I'm following the magenta line on Explorer charts. In areas where charts are less accurate, I'm more conservative. You can rely on soundings in the vicinity of active commercial ports, but in lightly used inlets, you need to check the datum to see how old it is. I went into an inlet on the Georgia coast where depth was ten feet different than what the chart said, and afterwards, I realized the datum was from 1983. Basically, if you can easily sail in deeper water, do so. If you have to traverse shallow areas, do your homework regarding chart accuracy and how recently the area has been surveyed. Get local knowledge if possible.

[Mike OReilly]

As others have already said, it depends. Depends on the location, the bottom, tides, and also how much is sticking down. I've sailed in shallow areas where I sure wish I'd bought that retractable keel boat .

It does take time to adjust from deep water sailing to shallow water. I recall sailing the length of the Great Lakes. When we left Lake Superior, where water quickly falls off to 100s of feet, it was freaky to sail through Lake Erie where the deepest parts are less than 100 feet, and often less than 15. Sailing over those well heads, I always felt we might be scraping bottom.

[Clivevon]

It depends.

[jim King]

Right on Bill. Along with that is your familiarity with the terrain under your keel. It you have sailed this stretch many times in the past with no difficulties and know it to be at least 3' under your keel and a good depth sounder I would feel confident in continuing.

[Clivevon]

Sometimes its a case of “I wonder if the bottom mud is soft enough that i can plough through it the last few feet to the dock now at dead low springs, or have i got to sit here for 30 minutes…”. It depends.

[Hhew]

It might be worth the investment of a few hours in a dinghy with a handheld depth finder to do a recon of the area of interest.