Navigating the shallows...your opinions

[sierra 18]

As a fairly new boater, I find I may be overly cautious in my habits.

My question is this; I have a 14' Lowe with a 35HP Johnson. I tend to lift the motor and use the trolling motor when I get closer to the shallows, but how shallow would you think a 14' aluminum V hull can draft before hitting bottom? Most of the launches I have used are only about 4'-6' around the docks.

I would rather be safe than sorry, but even with reading all the maps I can find, I realize that you have to be very certain of the water you are in since not every map can cover every inch of the water or deal with fluctuating water levels.

Let me know your advice for general water depth issues/concerns.

 

[Dave Abrahamson]

Re: Navigating the shallows...your opinions

Well...If it helps any, I have a 20 foot center console and i can get into about 1.8 to 1.5 feet before the bottom starts rubbing the sand/grass. I try not to of course. Mine isn't a flats boat by any stretch either.
Oh...and never boat where birds walk.....I'm just sayin'

Good luck
Dave

 

[convergent]

Re: Navigating the shallows...your opinions

Put your boat on the trailer and put the motor down in the position it would be when you are in the water. Measure from the water line on the side of the boat down to the bottom of the motor. That should tell you exactly what depth you'll make contact with the bottom. I am a little paranoid about this stuff too, and I'm probably trolling into shallow fishing areas from farther out than I really need to.

 

[nlain]

Re: Navigating the shallows...your opinions

If you can see your water line on the boat, measure down from that to the bottom of the skeg, motor all the way down and then motor trimmed up, that will give you total depth, or draft, then you can measure from the bottom of the boat to the bottom of the skeg to get how much water under the boat before the skeg hits bottom, then measure from the water line to the bottom of the boat, that will tell you how much water it takes to keep it floating instead of aground. I know a lot of measuring but it will get you close, all this can change depending on load at the time.

 

[dingbat]

Re: Navigating the shallows...your opinions

Nothing bets local knowledge of the area.

I official draft 14? (32? with the motor down) but get very nervous if I?m in anything less than 48" of water. Storms (shoaling), winds, and tides all have a big affect on the depth of the water at any given time. Not uncommon to see the winds change the depth of a big body of water by 12? or so on the windward side.

Not sure what measuring down from the water line is going to accomplish unless you normally use a ruler to measure your depth while on the water.

Determine your lowest point from the face of the transducer. At that point you have two options. You can either remember this number in your head or you can program the figure into your depth finder as an offset. The DF will then give you the depth from the lowest point of the boat and the bottom.

 

[sierra 18]

Re: Navigating the shallows...your opinions

Oh...and never boat where birds walk.....I'm just sayin'

Good luck
Dave

Love that......

All excellent advice gents, I will measure as directed here to establish a more exact knowledge of my boat's drafting ability. An ounce of prevention is worth a pound of cure, so not hitting rocks in the first place is the best bet.

Thanks for the replies all,

Chris

 

[Home Cookin']

Re: Navigating the shallows...your opinions

A lot depends on your bottom. I am eternally grateful for our mud and sand bottoms here; I wouldn't last around rocks. So there's your first "it depends" answer.

Get polarized glasses and also learn how to read the water; color and surface condition, the shape of the banks, current, all are tell tales (as are birds walking and crab trap tops). You can also feel it in the hull and engine noise.

The tricky issue is running on a plane over water that is too shallow to run slow. Your heart is in your throat the whole time.

 

[ufm82]

Re: Navigating the shallows...your opinions

Home, that's sooooo true.

While in Florida a few years back I wanted to fish a bayou area that was blocked by a large sand flat. The bayou was soooooo tempting that I had to try to get into it- I could hear the redfish laughing at me. "Nyaa Nyaa, you can't get me!!!" LOL

My boat draws about 20" at rest but comes up 12" when on plane or so I guessed. The sand flat on the map showed 2' at best. I waited until high tide and ran the flat on plane. (It was about a 1/4 mile wide) With the water being crystal clear it was a hairy feeling watching the bottom go by at 30 mph! However, I made it without a hitch and the water in the back area ranged from 3'-10' deep and was LOOOOOOAAAAADDDDEEEEDDDD with fish. Going back out during the next high tide was not nearly as bad but I knew that if I dropped off plane, I would stuck for who knows how long. Fun, scary as all get out and probably not the smartest thing to do but what the heck.

UFM82

 

[ewenm]

Re: Navigating the shallows...your opinions

i have a 32 foot sports cruiser and it gets scary when you see the depth gauge falling especially when you realise you have already pasted that point, i get the cold sweats when i see 3 feet, at two i start preying, where we boat there are two types of boater, those who have hit sand bars and liars,

i have a 2 foot safety margin built in to my depth gauge and find that gives me piece of mind.

 

[NSBCraig]

Re: Navigating the shallows...your opinions

I second homecooking's comment on polarized glasses.

Depending on the water you use different colors, here we use brown ones ( got mine at bass pro shops $9 and they float).

You can see the sand, so just stay in the blue areas and your fine.

 

[Home Cookin']

Re: Navigating the shallows...your opinions

never rely on the depth that is printed on a map, for sand bars and other shallow water features. Or read them after subtracting 2' if you want to be safe; give it a poke if you want adventure.

Another trick in unfamiliar water: follow the crab pot floats; they are usually set in the natural channels. PLus if you can't see the tops you know you have 18"

 

[Ned L]

Re: Navigating the shallows...your opinions

As a bit of perspective, it is not unheard of for large commercial shipping (freighters & tankers) to run with 6" between their keel & the bottom. Just know your current draft & the depth really well.

 

[Home Cookin']

Re: Navigating the shallows...your opinions

I wonder if for ships there is a hydraulic lift effect? I know that running a motorboat over shallow water is a way to get it up on a plane.

 

[capt sam]

Re: Navigating the shallows...your opinions

Home Cookin' pretty much nailed it, learn to read the water. In your particular baot I wouldn't be really concerned about hitting bottom, it's fairly shallow running and if you do hit, get out and push it off. And as advised never run where birds walk, it's good advice.

My boat will do close to 7" on plane, I've tried less than that a few times but strangely enough it never seems to make it.

 

[Ned L]

Re: Navigating the shallows...your opinions

I don't know if there is any "hydraulic life effect". If they do run aground, they can end up in a situation where the suction to the bottom will actually hold them down some.

 

[mpsyamaha]

Re: Navigating the shallows...your opinions

running at planing speed over very shallow areas is something any inshore fisherman in florida probably has done. i love doing it in areas i know well, its cool seeing the bottom rush by so close.

to the OP, i would think your little boat could go very shallow, i doubt the skeg hangs more than about 2 ft. fully down, and up on plane even less. i wouldnt worry too much... unless the bottom is all rocks, stumps, and oysters then you probably shouldnt go fast at all

 

[arks]

Re: Navigating the shallows...your opinions

Sierra 18-
I have a very similar boat (14' Lowe with a 25) and she draws 2' at rest. On plane the boat can run in 18". There's no rocks where I do that kind of thing, LOL.

I wonder if for ships there is a hydraulic lift effect? I know that running a motorboat over shallow water is a way to get it up on a plane.

I remember reading an article about the QE2 hitting bottom up in New England a few years back. In that article they said a large ship running at high speed will actually draft MORE than when at rest. Has something to do with hydrodynamics. Thought that was pretty interesting.

Here's a little blurb I found about it on Wikipedia:
'On 7 August 1992, the hull was extensively damaged when she ran aground south of Cuttyhunk Island near Martha's Vineyard, while returning from a five day cruise to Halifax, Nova Scotia along the east coast of the United States and Canada. A combination of her speed, an uncharted shoal and underestimating the increase in the ship's draft due to the so-called squat effect led to the ship's hull scraping rocks on the ocean floor. The accident resulted in the passengers disembarking earlier than scheduled at nearby Newport, Rhode Island and the ship being taken out of service while repairs were made in drydock. Several days later, divers found red paint on previously uncharted rocks in the vicinity of where the ship was said to have hit bottom.'

 

[capt sam]

Re: Navigating the shallows...your opinions

on the tiller motors we unlock the motor so if we do hit, it just pushes it up...the downside is sometimes they lock at the top and are running out of the water which is a real attention getter.

 

[bob johnson]

Re: Navigating the shallows...your opinions

if you worry about shallow areas that you boat in, you are gonna have to spring for a depth finder!!!


and lern your area...my area has a ton of obstructions and rocks...LOADED


i know that many lay 5-7 feet above the outerlying area... and as such once I get to a depth of 7 feet I slow down in areas i am not familiar with...and I watch the depth finder....a chart platter would make life even easier...but realize it doesnt show up much on 14 footers..

if you get into your safety zone, go back and put the motor in shallow water drive...

make sure your cav plate in not BELOW the bottom of the hull....carry spare props and a wrench to change out...



good luck

bob

 

[sierra 18]

Re: Navigating the shallows...your opinions

Really good info gents, thanks for the informative replies.

Yep, up here in Canada, on the lakes there's LOTS of rock, good, heavy, ancient glacial deposits of slab and boulders. I was recently trying to get close to a shoal on a lake to cast, but the water dropped from 30 feet on my sonar to the visible change of seeing blue-deep-water-to-sandy brown-of-big rocks in a matter of a few feet.

As I used the trolling motor to carefully move my way in with short taps on the foot pedal, I kept my eyes peeled 'till it was about 3 feet deep, then I tossed out the anchor. I still felt skittish, since waves were pushing us towards the rocks, causing some interesting discussions between me at the stern and my wife at the bow over whether to weigh anchor and move back a bit........

Hitting a sandbar is one thing, but hitting them rocks that look like bowling balls for giants, well, I like the advice of knowing the water, wearing the polarized sunglasses, obsessively watching the sonar and getting to know a new body of water carefully. Oh, and treading carefully while carrying a spare prop.

Thanks for all the replies, really great folks on this forum.

Chris