As Captain Dave notes below, it’s a very good idea to call the bridge tender prior to your arrival at her/his span, to check on the latest vertical clearance stats.
However, a check of chart 11534 shows the official closed vertical clearance of the Socastee Swing Bridge is 11 feet, as noted below by Captain Donavan.

Subject: Bridge clearances
Cruising News: The Socastee and Wrightsville Bridges both have 20 foot clearances listed. When we passed Socastee they had 22 feet which allowed us to pass without an opening – and Wrightsville Bridge a short time later had 17 feet which did require an opening as we need 20′. We learned that a call ahead to ask what the real clearance is proved useful.
Dave
on GB 46 At Last

The socastee bridge clearance is 11 feet
Donovan

The “Pine Island Cut” section of the AICW (which runs behind Myrtle Beach, SC) has long been known to Waterway veterans as the “Rock Pile.” That’s because there are all sorts of underwater rock shelves, waiting to trap those who deviate too far from the Waterway’s mid-width. Looks like Captain David found one of those “rocks” in his account below!

Cruising News: At approximately SM 347.4 (the rockpile section starts at SM 350.1) we found a rock on the red side of the channel. We obviously strayed too far to the right southbound and were greeted with a grinding sound as the keel ground its way across the top of the rock. The guide books are correct. Stay in the middle.
Dave
on GB 46 At Last

On 9/1/09, as part of a “South Carolina Wish List,” I posed the following question:

2. . Has anyone visited any of the three marinas on Coquina Harbor in Little River recently? What depths did you find during your visit? Does Myrtle Beach Yacht Club (on the harbor’s northerly shores) still have some of the best fuel prices on this portion of the Waterway? Has anyone eaten at the adjacent Umbertos Restaurant lately? Do they still have the BEST chops on the Waterway?

Responses follow:

I have a condo at Coquina Harbor. Depths have been good since the dredging of the harbor was completed. I have a shallow draft boat, but I asked the owner of a 6.5 foot draft sailboat that stays here how he found depths throughout the harbor. He said he had seen nothing less that 7.5 feet at low tide. This inquiry was made 9/04/09. I came through the entrance at high tide on 9/05/09 and my depth sounder indicated 14.5 feet. When I really want to reward myself, I have pork chop at Umburto’s.
John Lyon

Click Here For The Cruisers’ Net’s South Carolina Marina Directory Listing For Myrtle Beach Yacht Club

Click Here For The Cruisers’ Net’s South Carolina Marina Directory Listing For Lightkeepers Village

Click Here For The Cruisers’ Net’s South Carolina Marina Directory Listing For Coquina Harbor Yacht Club

On 9/1/09, as part of a “South Carolina Wish List,” I posed the following question:

5. Has anyone stayed at the Marina at Grand Dunes, near #22B. Were you as impressed as this writer?

Responses follow:

We stayed at Marina at Grand Dunes for 4 days and enjoyed the peace and quiet, dog friendly, beautiful pool, clean facilicities, and very friendly, accommodating staff. The docks are great and it is very well protected marina. There was no courtesy car, but the hotel van will take you to their private beach. We rented a car while we were there. We would definitely stay there again. It was like a mini vacation!
Barbara and Jim Benjamin
Golden Lily – Nordic Tug 42

We are here- 9-3-09 -for the 2nd time from about 1 year ago. Came up from Isle of Palms, SC’“ about 100 mile trip. Marina at Grand Dunes is Great!! Dock hand Adam is friendley and knowledgeble. Boat US discount for 1.75/ft’“ includes power, wifi, cable, etc. Have not gone to Ruth Cris’s or Anchor Cafe, which is overlooking- literally- the ICW, but will tomorrow. Docking is EASY since no current at all. Definately recomend Marina at Grand Dunes.
Charlie and Jackie on Elixir

Click Here To View the South Carolina Cruisers’ Net Marina Directory Listing For The Marina at Grand Dunes

On 9/1/09, as part of a “South Carolina Wish List,” I posed the following question:

4. Has anyone stayed at the Barefoot Resort Marina, west of #22, within sight of the three HUGE high-rise condos. Our fellow cruisers would appreciate a report.

Responses follow:

Have stayed twice at Barefoot resort – 2 years ago – was great facility, rest. was very good, dockmaster the best. Was very new at the time – fine facility. At that time was off the beaten track, but the Myrtle Beach track keeps growing!
John Wild

We spent over two weeks with Bill, George, and the rest of the crew at Barefoot Landing Resort this summer. Great marina, great price (1.50 ft Boat US), and good fuel price. It’s very hard to beat this price for transients. It’s a bit of a walk to the grocery store or the shops and restuarants across the waterway. Though we didn’t partake, I understand there is a shuttle to the beach. The laundry facilities were clean and the equipment worked well. Will stay there again when we transit this section of the waterway.
Perry & Kathy

Click Here To View the South Carolina Cruisers’ Net Marina Directory Listing For Barefoot Resort Yacht Club

I’m so glad that Captains Perry and Kathy had such a good time at Barefoot Landing Resort. I have always been equally impressed with this facility. Of course, why should that be at all surprising as these good people are a SALTY SOUTHEAST CRUISERS’ NET SPONSOR!

We thoroughly enjoyed Myrtle Beach’s Barefoot Landing Resort Marina. Dockage fee, 1.50 per ft (Boat US), great facilities, and very convienent for shopping and restaurants. We enjoyed the fare at Gregg Norman’s a couple of different times. Nice place to eat while watching a sunset.
Perry & Kathy Sellars
M/V Marsh Mellow

Click Here To View the South Carolina Cruisers’ Net Anchorage Directory Listing For Barefoot Resort Yacht Club

Why am I not surprised that there is confusion about the Socastee swing bridge opening schedule. What else can you expect from a span that should have been removed the minute the adjacent high-rise bridge was completed!

Subject: Socastee Bridge Opening
Cruising News: Two weeks ago, having seen your comments that the opening of the Socastee bridge is now "On Demand" versus every half hour, I rang the Bridge for myself and they confirmed that that was the case except maybe during school hours.We were due to go down that next weekend and the Operator told me it would be an "On Demand" schedule. We transited south last week and when we got to the bridge, we requested an opening and were told it would open in 15 minutes. On the way back up north, we were told that it would open in 10 minutes. I called the Bridge and asked what the policy was and this Operator told me that the Bridge will open again 15 minutes after it last closed. So, I guess it's a semi on demand process, but certainly confusing. Maybe you could clarify the policy for everyone!
David Kelly

Myrtle Beach Yacht Club, a transient friendly facility, with great fuel prices (and they are a SALTY SOUTHEAST CRUISERS’ NET SPONSOR) is located in Little River, SC, in Coquina Harbor. Below, Captain Chris gives this facility very HIGH marks!

Subject: MYBC Officers’ Club
Cruising News: Not wanting to get back out in the Myrtle Beach Bikers Rally, we went to the Marina’s Officers’ Club restaurant (actually a private club), and we were very pleased. This was a 4.5 star dining experience. I have had bad luck with gumbo this trip so this time I asked for a taste. I was brought a condiment bowl on a doilied saucer with the gumbo, rice and garnish. It was Seafood Creole (almost a Cioppino). But it was very good creole!
After excellent shrimp with Thai Chili sauce for an appetizer, when the creole dinner serving arrived, it was literally beautiful. A cookbook cover photo. My wife’s stuffed flounder was every bit as well prepared and presented. Ryan, waiter, did a great job.
The Marina has been an excellent place to keep the boat for a week while we took care of land side must dos. We strongly recommend this secure, clean, well run establishment.
I need to add that MYBC’s capital investment in new head and shower facilities paid off. The new arrangement is excellent.
Chris Waln

Click Here To View the South Carolina Marina Directory Listing For Myrtle Beach Yacht Club

The Pine Island Cut is tricky enough, with all its underwater rocks lining both sides of the canal. Throw in some less than responsible speed boat operators, and this can be a real problem!

Subject: Dangerous Behavior MM 347 to 355
Cruising News: Mothers' Day when transiting the Rock Pile at half tide falling, we were passed at 45-55 mph by two 40+ foot deep-vee boats (Cigarette-like, both white one with red and blue and the other with red and yellow graphics). 
The first boat passed us westbound 60-70 feet away.  When he returned east bound, he was 30-40 feet off our beam. 
The second boat came up from behind us at speed as we were approaching the new bridge near marker 15.  She passed us 10 feet off our port side throwing water on our deck.  The young female operator turned to look back at us with a big "gotcha" grin and looked forward just in time to avoid smashing into the bridge construction equipment.  Her speed never varied, and we pegged her on our radar at between 47-53 mph.
I discussed this with a local fisherman the next morning at MBYC.  He nodded and said it was a real problem in spring and fall weekends (mostly) when it was too chilly or rough offshore.  He didn\'t know of, and I couldn\'t find any reference too speed limits in this rock-challenged congested area.
You can't hear these boats coming unless the wind is behind you, and you are distant from the sound of your own engine.  They can travel a half mile in 35-40 seconds.  So a glance backwards now and then is only randomly helpful.  We've set our radar alarm to warn us of traffic much farther astern now, But that\'s only party useful.
Chris Waln

Of course, the Marina at Grand Dunes is a SALTY SOUTHEAST CRUISERS’ NET SPONSOR!

Hello all:
Palmetto Moon with Jim, Su, and Alex (the lazy cat) are at Marina Grande Dunes (mm 357).
This is a great stop because:
Clean
Great docks
Free pump out
Dock hands know their stuff
Free cable
Coffee in AM
Free WiFi
3 restaurants on site
Pool
New supermarket across the street
Shuttle van for longer trips.
Hope this helps. As always YMMV
Jim, Su & Alex (the lazy cat)
Jim Cobb
Palmetto Moon

How about even more praise!

Subject: Grande Dunes
Cruising News: We’re docked across from Palmetto Moon at the Marina at Grande Dunes waiting out the latest storms. Two important things were left out of their report: a free bottle of wine is presented on check-in along with a $25 gift card for the on-site Ruth’s Chris Steakhouse. If you drink the wine before you go to dinner and order off the “Prime Time” reduced price menu and then hand in your gift card, you can get a great meal at a much more reasonable price. Also, we just got back from the new grocery – Lowes Foods – and it’s spotless. This is becoming a favorite stop on the ICW.
Bill
“Tapestry”
Krogen 58

Click Here To View the South Carolina Cruisers’ Net Marina Directory Listing For Marina at Grand Dunes

Hmmm! If Captain Pat took her soundings, described below at "half tide," low tide depths could be as shallow as 7 feet.

Subject: Inlet crossing updates
Cruising News: April 8 2009 Little River Inlet ICW crossing followed magenta line nothing less than 10 feet half tide.
Pat Banyas
s/v Marguerite

South Carolina Yacht Club, which is actually a transient friendly marina with GREAT fuel prices, and a SALTY SOUTHEAST CRUISERS’ NET SPONSOR, is one of three facilities located in Coquina Harbor (in Little River, SC). Not only is SC Yacht Club a good marina, but Umbertos Restaurant is just next door. To say the food here is good, is to say something like the sun is kinda bright!

Cruising News: Stayed at Myrtle Beach Yacht Club. $1.35 dockage with US Boat and nice place. Great restaurant on site.
Patty Mitchell

Click Here To View the South Carolina Cruisers’ Net Marina Directory Listing For Myrtle Beach Yacht Club

Little River Inlet intersects the AICW, immediately south of the North Carolina – South Carolina state line. In fair weather, I've always found this inlet to be reasonably easy to navigate, but the easily run inlet (at least for 100% of the time) has yet to be invented.
The discussion below was copied from the AGLCA list.

Little River Inlet at the State Line between SC and NC is fine, but not in Skipper Bob.  It's well marked and carries 12' – 15' feet the entire way.  The one area where it shallows is where it meets the ICW; stay in the middle until you get into the ICW channel.  The casino boats use the inlet every day out of Myrtle Beach.
We use Little River often, weather permitting.  It's just 25 NM to Cape Fear, and it's an easy, straight run.  No need to go miles offshore to clear shoals.  The advantage has been to avoid Shallotte's
Inlet, Lockwoods Folley and the Poontoon Bridge.  So it's a 3fer…
We're a 7.3 kt boat, and we frequently hear boats on the ICW – ahead of us at Little River – behind us at Southport, and vice versa.  So if the wind is 15 – 20 kts, we go outside between Cape Fear and Little River.
Peg and Jim Healy aboard Sanctuary

You can comfortably add the Llttle River inlet  on the North/South Carolina border as a safe daytime entrance.   This excellent inlet, about 30 miles west of Cape Fear, is used daily by two large gambling boats and by several big fishing "head boats" and some shrimpers. Better yet, less than a mile inside  and just across the ICW is a frequently used anchorage on the NC side of the channel.  It is pretty exposed to wakes, but most of the head boats will slow for you if you are well lit,
This is not a well lit entrance or inside channel, so , while it can be done in the dark, I don't recommend it for a first time entry.
Conversely, if you come north on the inside , you can avoid a slow 30 miles from Little River to Southport, including the often shoaly Lockwood's Folly and Shallotte sections, and the once-an hour Sunset Beach pontoon bridge by going out Little River and back in at Cape Fear.  No off shore obstructions, so you can basically run the beach almost all the way…
Olrick

Little River SC inlet is very easy to navigate. It is well marked and right on the SC/NC border, after entering inlet go just south 2 miles, on the ICW and you have numerous choices of overnight very nice marinas,
John M. Beaver

In the last edition of “Cruising Guide to Coastal South Carolina and Georgia,” I warned that the entrance to Calabash Creek was shoaling, and that low water entrance and egress from this popular anchorage could be more than slightly tricky. Looks like Captain Jeanie’s report bears out those observations!

Our adventure was not over. Our intention was to anchor in Calabash Creek. However, we knew we were now only 1 ½ hr before low tide and that this could be a problem. We left flashing green daybeacon 119 and crept toward red floating ICW R2, eyes on the sounder. DON’T DO THIS. Stay mid channel on the ICW. There is shoaling well out from the northeast at Calabash Creek. We had about 3 hours to watch shrimp boats and casino boats traverse this section, as we sat aground in the ICW channel just over the midline to the northeast in the ICW and east of red floating 2. We didn’t feel quite so inept, when we watched a shrimp boat go aground just in front of us as he came in from sea and crossed the ICW to go into Calabash Creek. He was able to wiggle off, however. By 1930 we thought we had enough water to work our way into deeper water, and persevered when we cited two shrimp boats returning from sea. They crept through the creek entrance and we followed them in. Of course it was now dark but we only went in enough distance to anchor in 9′ of water. That anchorage had been so close and so far away.
No problem leaving at 8 this morning, and we had a great run to Georgetown.
Jeanie Quigley

Click Here To View the South Carolina Cruisers’ Net Anchorage Directory Listing For Calabash Creek

First, please note that Captain John's note below refers to the dock off Barefoot Landing Shopping Center, NOT Barefoot Landing Resort Marina. These two facilties sit on opposite sides of the AICW – Pine Island Cut canal.
With all that out of the way, be SURE to watch out for the pesky shoal John describes below!

Subject: Barefoot Landing, SC Low Spot
Cruising News: There is a sailboat drawing 6' hard aground 150'north of the east end of the Barefoot Landing docks (just as you pass south of the Barefoot Bridge).  Low tide was at 1445 but they were aground at 1230.  (The sailboat is out in the ICW 150' from the docks…) Watch out for this low spot.
John Loving

Personally, I don’t think there is really any doubt that Barefoot Landing Resort Marina is one of the very best of the best when it comes to a discussion of South Carolina marina facilities. Of course, I’m prejudiced, as these good folks are a SALTY SOUTHEAST CRUISERS’ NET SPONSOR!

Subject: Barefoot Resort Marina
Cruising News: Just a note to say what a great deal Barefoot Resort Marina is. It is right across from Barefoot landing. Dockage is $1.50/ft which incl elect, water, cable, etc. Laundry room just off the dock. Have to walk across Barefoot Landing Bridge to shopping (3/4 mi).
John Loving

Click Here To View the South Carolina Cruisers’ Net Marina Directory Listing For Barefoot Resort Yacht Club