R21EC shallow water questions

[DMcD]

newbie with a 2013 R21EC in the North Alabama section of the Tennessee River and its lakes with some questions:

1. How shallow can she go? The manual says the draft is 24" and I've heard a rule of thumb is to not go shallower than twice the draft - does that hold true for an R21?

2. What happens if she runs aground? Will the propellor get damaged?

3. If propellor becomes fouled with weeds will a reverse rev be enough to clear it?

4. I mounted my transducer at the aft end of the starboard berth compartment... what's the best offset from my Garmin?

thanks for your patience

 

[bob daily]

Just my opinion on your questions
1. I have my shallow water alarm set at 3 ft
2. Depends on type of bottom (sand, mud, or rocks)
The propeller should be (somewhat) protected by the Skeg.
3. Depends on how bad it's fouled! I've cleared seaweed, kelp, and a small piece of drift wood,
By placing in reverse.
4. The location of your transducer is about 6 inches below waterline.

Hope this answered your questions. Bob

 

[DMcD]

Just my opinion on your questions
Hope this answered your questions. Bob

Thanks! Very helpful.

 

[REO6205]

Bob Dailey gave you some good advice but I'll add one thing. If you're operating in shallow water, especially with a mud bottom, you can suck up gunk into your engine water intake. This happened to me in the Sacramento Delta running my crawdad traps. I was running in about three feet of water and sometimes probably less than that.
The water strainer was partially plugged with mud and weeds and the intake line was clogged too. My son was fishing near me and we used his wash down hose to back flush the intake lines and wash out the strainer.
I pulled the cover on the impeller and there was no mud but I back flushed the engine using the fresh water cleanout fitting anyway.

 

[iggy]

Bob Dailey gave you some good advice but I'll add one thing. If you're operating in shallow water, especially with a mud bottom, you can suck up gunk into your engine water intake. This happened to me in the Sacramento Delta running my crawdad traps. I was running in about three feet of water and sometimes probably less than that.
The water strainer was partially plugged with mud and weeds and the intake line was clogged too. My son was fishing near me and we used his wash down hose to back flush the intake lines and wash out the strainer.
I pulled the cover on the impeller and there was no mud but I back flushed the engine using the fresh water cleanout fitting anyway.

Just to add to this point. If you suck up sand it will ruin the impeller and maybe its housing. So know you bottom 😀 . Personally, I will not go below 6 feet. I have hit rocks and won't take that chance any more. BUT I am from Boston and its not uncommon to see 3 foot rocks sticking up.

 

[Capt’nKarl]

We live and cruise in the Florida panhandle where there are many beautiful and shallow spots to explore. Very often we carefully and SLOWLY intentionally run aground to explore these new beaches. After 9 years of boating we’ve NEVER had any issues getting stuck, getting sand in the raw water intake or any other significant issues. The worst case scenario is I jump overboard and push us off. Go explore, be cautious but don’t let shallow water hinder your adventures.
Cheers,
Karl and Sara

 

[tjcouch]

In addition to the concerns of clogging up your coolant intake, I'll share a story.

First: Volvo D1-30, is my engine.

I found myself cruising with a fair amount of floating duckweed. I surmise it clogged my intake, and my strainer basket while cruising to my favorite island from the river into the bay.

After stopping for a break/swim/snack, when I fired her back up, I did not see the wet part of the wet exhaust.

Mercifully, there was never an overheating of the engine. But I did observe there was something not-right.

I shut back down, checked the basket, and it was quite clogged. After cleaning it, I restarted hoping for the best. I was disappointed.

Using only a flat screwdriver I opened the impeller housing and found only one blade remaining. It was enough to move cooling water poured into the basket by my wife, but not enough to pull water through the loop. We idled to the nearest ramp, about a mile away, with my wife continuously scooping and pouring water into the basket. Called an Uber from the ramp to take me to my home to fetch the trailer.

Yeah, the Mrs. was a real trooper - if she had not been aboard, I would have been waiting hours for a tow service, or prevailing upon the good nature of another boater, and hoping they have a clue about towing.

Back at home, after receiving the replacement impeller from Amazon, it took all of 5 minutes to replace the impeller, using only a screwdriver.

Tip: keep a spare on board. I do now!

 

[iggy]

In reading some of these post, something just hit me. Tides!! In Boston we have between 12 to 13 foot tides. Never boated in Florida, but thats more like 2 to 3 foot tides. So if your going into shallow places the tides must be considered. Maybe I am saying the what everyone already knows!

Oh well, just be careful out there.

 

[Fisho]

The key is whether you are in familiar waters or exploring new areas. For new areas I rarely go less than 1 metre (3 feet) and usually more especially if a rocky bottom, and of course I am very careful. I closely monitor the depth sounder and side scan sonar if in shallow waters. I have the Shallow Water Alarm set for 0.7 metres. In familiar areas with sandy bottom with a few weeds I regularly cross some shallow areas about 0.7-8 metres (2.5 feet) to get to some favourite moorings but I am very careful. Remember one of the benefits of the 21EC is that it does have a shallow draft and if careful you can explore some amazing areas that are shallow. Only once have I touched the sandy bottom. I have never had a problem of blocking the raw water intake or damaging the impeller. For obvious reasons I never use the Autopilot in shallow areas.

I regularly check the raw water strainer and the impeller although often a bit of rubbish in the strainer that is easy to clean. I always carry a spare impeller but have never needed it. I have replaced the brass cover on the impeller with a Speedseal Life cover (see previous posts). This makes it VERY easy to remove the impeller cover to check if ok and also minimises the impeller getting damaged due to a blocked intake. The Speedseal is designed to be removed and replaced with no tools. One of the best modifications I have made.

 

[bob daily]

As others have noted the problem with grounding your boat is fouling the sea water intake. The easiest way to clear is to back flush. This has a potential to hydro-lock the engine if not carefully, and now you have a worse problem! To eliminate the potential of this is to add a valve between the fresh water flush fitting and the raw water pump. If you have a wash down on your boat, simply close the inline valve and hook up your wash down hose to clean strainer.
I am awaiting parts for this modification and will post back when complete. I see nothing wrong with a soft grounding on a soft bottom as long as your prepared! I'm doing this modification so I can use a friends dock that will put the boat grounded at low tide, however the fishing is great in that area!
Bob

 

[Catch22]

Does anyone know if the Speed Seal and Teflon washers are being made anywhere now? Hard to believe something that utilitarian does not have a following.

 

[Pilotnavigator]

Don’t think they are made any more, but on a 21 how could you make changing the impeller any faster! It is the easiest access to one that I have ever seen!

 

[bob daily]

The web site ( safety@speedseal.com ) says they are no longer in business!

 

[Fisho]

Speedseal is a great product but now out of production. It seems some companies carried stock and had a few. Was the case in Australia. I would have thought a lot more were imported to the US? Don’t know. If interested you might want to ring around or check on line? Good luck.