Snorkeling! Swimming!

Snorkeling carries it’s own hurdles to do for a type 1. I love snorkeling and wasn’t going to give it up just because of being a type 1. Although I have made concessions along the way.

When I first was misdiagnosed as a type 2 and I was put on insulin and I tried to snorkel, I actually did not know the huge pitfalls of lows or highs. I was literally handed Lantus and told to start taking it without any guidance other than start out at 10 units and add 2 units every couple of days until it works. So of course the first attempts at snorkeling I crashed bad after snorkeling and quickly learned to start out at a higher BG level and cut back on how much Lantus I was taking. Progress a few years, fast acting insulin added, properly diagnosed type 1.

That first time was the hardest, it then took some trial and error to figure out the best route for me, which might not be the same for someone else…

1) Ginger candy for me or another quick acting sugar in a waterproof container. The first time I used it out in the water it had leaked…yuk salt water ginger candy.

2) Start out higher than you like because you will drop, in my case I start at 130-150. It’s hard to get an exact number to go in the water when I have to boost my normal Bg level and I want to avoid taking insulin before I swim.

3) I do a 50% Temp basal reduce on my pump a half hour before I start for 2 hours. . I had read it’s better to stop the rebound high afterwards by doing a temp basal decrease instead of suspending basal altogether. That does seem to help stop it. I might try to reduce that a little more as I have come out of the water at 75-80 sometimes, but I believe that is when I have started out at my lower level range. So I am now thinking about varying the temp reduction with my start number.

4) I limit my snorkeling to about an hour. This is one of the concessions I have made being a type 1. I used to be able to swim forever with no thought to Bg levels. I can’t really tell when I’m going too low snorkeling. Once I was shivering, that anxiety feeling, so I got out and my Bg level was 90 so I must have just been cold. One time I got a tremendous headache I got out and I was 65. But an hour seems to be a safe number. I have been known to chomp a few pieces of candy to stay a little longer.

5) You should always go out with a pal. I say that and I have taken to snorkeling by myself now sometimes. But I am snorkeling consistently now. Again the first time was scary. But the areas I go by myself have a lifeguard(s) in sight, hopefully if I start waving my arms they would spot me, but also where standing up in the water isn’t that far away.

**6)**I keep closer to shore or a boat. I used to follow reefs way out into the ocean and while some areas I go are a little farther out, that is in areas I have been closer and experimented with before I stray farther out.

This disease is unpredictable and allowances have to be made, I start out higher, I limit time. Sometimes I have exited the water at 75, sometimes at 120. I hate going into the water at 150, but it’s safer to be too high than too low. You can’t always tell how much work it’s going to take in the water with the currents etc. But I am blessed to now be in an area where it has some of the easiest waters to snorkel in.

I am also thinking about adding a Libre to my Dexcom lol…They have improved waterproof holders. I have one for my iphone now and I was hoping when out in the ocean I could keep my arm out of the water long enough to get a reading from my Dexcom. But that hasn’t worked at all. It would be so nice to be able to see my Bg level when I am out in the middle of the ocean.

When I wore a Libre, it handled the ocean just fine (for me) I would get a reading as soon as I got to my car by scanning. The Dexcom wants to download all the missed data so it takes time to get a reading. So even holding my arm up out of the water hasn’t worked. But I don’t want to give up my Dexcom. So I am thinking about getting a Libre too, put the reader into a waterproof pouch so I can scan when I am out there by just lifting my arm out of the water. When I had my Libre the waterproof containers were hard containers so you couldn’t press any buttons and they weren’t completely reliable to chance taking expensive equipment into the ocean. Now they have pouches that have worked really well.

Be aware neither Dexcom or Libre guarantee their sensors/transmitters for being in salt water. I have heard someone had trouble with their Libre going after being in salt water. I have never had a problem yet, but it doesn’t mean it won’t. Just like your iphone might be water resistant, but drop it in the ocean and it’s potentially a different story.

So I am thinking about wearing a Libre too. If anyone has any input to getting a BG while you are out in the ocean swimming I would appreciate it!

And if anyone has any input on how they handle snorkeling or even swimming in a pool, I would love to know how you handle it!


Thats a lot of interesting info. I can tell you are a professional diabetes snorkeler. Swimming always makes me nervous. Good to know who the expert is.

It is obvious you have excellent control and you said you don’t like starting out at 150. Do you feel poorly at a higher number? I know from kayaking and other water sports, my DD eats a long lasting complex carb and protein beforehand and has less worry. She starts out a lot higher than 150 though and drops significantly, then gets back into good range when back on land. It’s not for everyone but her temporary high blood sugar is less worrisome to her than a low blood sugar that interrupts or shortens her activity.

I don’t feel bad at being at 150. I am just not used to being at 150 and not taking insulin for it? Usually if I see that number I want to fix it. So to purposely eat to make my blood sugar go up to that number irks me lol!!!

If I couldn’t do a temp reduction of my basal I would have to start out at a higher number. If I was going to be out longer than an hour I would have to start out at a higher number too.

@Marie20, I know that Bluetooth does not reach far under water. But it might reach a couple of inches. Have you ever tried to keep the phone close to the transmitter?

I’ve only been snorkeling once and I overestimated how much energy it would require.

I’m used to swimming laps for 30 minutes 2-3 times a week- though that stopped with the arrival of SARS-COV-2.

I went to Belize last year to snorkel near the Mesoamerican Barrier Reef. I was worried about lows, so I reduced my basal for the day.

In reality, snorkeling was much easier than walking or hiking - which I’d done a lot of in the few days prior. Since the ocean waves break against the reef, the snorkeling in this location may be easier than it is in other areas. I found that I was basically just floating along with the occasional kick. On Lantus, that just isn’t enough to create a downward trend for me.

In addition, the lovely men who took us out for snorkeling brought the most delicious pineapple! I definitely regretted the decision to scale back my basal dose that morning.

I’m not sure how will handle it next time, but I’ll probably rely more on snacks to bring up my bg level if I drop low rather than scaling back my basal insulin. It just wasn’t necessary.

My sensor worked fine, but I still tested my bg level anyway whenever I got back in the boat.

@Helmut I have tried to hold it right up to the transmitter. In the water it can’t communicate well and maybe I didn’t give it enough time. And when you are swimming out in the ocean and you try to hold your arm above water you can only do that for so long. So there again probably not enough time. I have swam to shallower water so I could stand and get a reading, but that’s kind of a pain to leave an area and swim back out to it. The problem is Dexcom wants to communicate all the past data first before it gives you a reading? So unless it’s continuous communication it wants to do that first.

I could try to tie my phone to the sensor lol…but I have been using my phone to take pictures and videos, But that gives me an idea that maybe get another pouch for the reader and strap it to my arm/sensor? But I have been getting some beautiful pictures and video with my phone.


@katers87 It just depends where you snorkel and when. It can be really easy sometimes, pretty kickback. Where you just swim out to an area and just float about.
There are some areas that are really easy places to snorkel. Hanauma Bay in Hawaii is one of the best and extremely easy areas to snorkel. Hopefully still as I haven’t been there for years. That is the first place I ever snorkeled at as a teen. It’s what made me fall in love with snorkeling. Beautiful Bay.

There are easy areas and some that take a lot more work swimming. Plus the ocean has currents that can take a lot more work on one day and not the next. So just be prepared.

I strapped my iphone to my arm on the transmitter on the swim out and it still wouldn’t give me a reading…sigh it just does not want to communicate under the water for me!

1 Like

@Marie20, thanks for conducting this experiment. I am glad that I did not bet on the outcome.

What did you use to strap it to your arm? Sounds like it could be a helpful accessory.

The Stash waterproof pouch comes with 2 cords you hook onto whatever you want so you don’t lose it. In my case I hook them onto my bathing suit straps. I just used one to wrap it around my arm. This probably wouldn’t be the most secure thing to do if you wanted to keep it there for a while, but I knew I wanted to use my phone for pictures and it just had to make it out to the area to test if it worked.

But if it worked I was going to order another Steaz pouch and an armband for the reader to stay on my arm, but now maybe for a Libre reader I am considering adding.

But there are armbands/straps you can buy that are much better, this is one I was eyeing. I have used an ace bandage if I wanted to keep something on my arm before. But that doesn’t work well if it’s something you want to pull off and on.

I have now come across a couple of articles that talk about a Libre working for scuba diving. It’s all someone says type thing, but hopefully there is some basis to it!!!

So I have ordered another waterproof pouch, put in a prescription request and I will give it a try!!!

Success everyone!!!

I got the new Libre2 yesterday, went snorkeling today!!! I have the reader in a Waterproof Stash Pouch.

It reads underwater!!! Really easy! I swam for 2 hours! I went in at 115, I had eaten something so I knew it would go up. It went to 119, down to 105 stayed there a while and back up to 120 by the time I got out! It is reading about 25 points under what I am , but that’s okay for my purposes. My husbands ankles were getting tired or I could have stayed longer! I’m so excited! not having to worry about what my Bg’s levels actually are is a huge plus, it gives me a lot more freedom to stay out as long as I want!


@Marie20, will you wear the Libre2 in addition to Dexcom?

@Helmut. Yep! I have the Dexcom on my left arm and right now the Libra on the inside of my right arm. I think I will move the next Libra to my love handles as some people have said they have had great success with them there. I would like to save my arms for the Dexcom.

Even though the Libra2 is supposed to be more accurate with this new one, it is still 20-25 points below my blood glucose meter test while the Dexcom is within 5 points. So there is no question I want to keep my Dexcom. For my purposes I just need an idea of what my BG levels are doing with the Libre.

Right now we are snorkeling twice a week, the water is warm and Northshore is calm in the summer. And while we can snorkel all year round here, in the winter the water is a little colder, it’s almost always the Southshore only and I doubt I would care as much staying out longer on the Southshore snorkel areas. They are smaller areas. I do use the snorkeling to just swim too, just longer laps than a pool.

I have been able to safely snorkel for an hour and once I came back into shore to get a reading and went back out so I stayed a total of two hours, but by the time you go in in a couple of areas you have a tendency to just go in for the day. And a couple of times I have come out at 75-90 BG levels.

So I might skip wearing it part of the year. It’s just you can’t always know how much work the swimming will be. I am not dropping as much now, I actually have my BG level staying even keel more or it has increased on me sometimes. But you can’t predict what it will always do and I’m out in the ocean, a ways from land a distance sometimes and no lifeguards at half the areas. So I look at the cost of it as being a safety issue and right now the same cost as if I belonged to a gym.

That would be the other solve is just go in at a really high number. I have done that too, but it goes against the grain to do that twice every week. That is a choice to make too. It was just so liberating to be able to know while I’m out there what my levels are doing!

My next attempt might be to wrap the Dexcom receiver in the pouch with Saran Wrap lol on top of the sensor so it stays right on top and see if I can get a reading. I will look weird but if it works!!! And if it works I can get creative with a wrap. I only managed once so far to get a reading with it while out swimming. It’s that wanting to download all the data while it can communicate in very limited windows that’s fouling it up. You can see little lines try to form sometimes when trying.


@Marie20, thanks for the detailed explanation. I am using an elliptical right now and start at about the same BG level after breakfast. Everything is supposed to be the same but the outcome is not. Sometimes my BG goes slightly up, sometimes I have to stop after 20 minutes and eat glucose tablets. I feel safe because I have my Dexcom in front of me. This peace of mind will be worth the cost of a Libre2 once I start swimming. We are building a house with pool in Florida.

What fun, so you decided on Florida! Near enough to an ocean I hope to enjoy it. I have a cousin that lives on the east shore on one of the many narrower strips of land. She loves it.

I ride my exercise bike 10 miles every day and like you sometimes after a few miles I have to stop and eat something because I’ll just nosedive. That always bugs me, that I have to eat something to exercise!!! It just can be unpredictable for no apparent reason sometimes.

I have made snorkeling work because I love it so much. Especially swimming with the turtles. But it was so much nicer knowing what my levels were!!!

1 Like

We have not given up on Kauai. The plan is to visit for a couple months when it is really hot in Florida. This is after we retire which is TBD.

1 Like

From out in the water! You can sort of see a dark patch in the top left part of the water. That’s a turtle coming up for air. The land is a pretty good distance. But this is a huge calm area in the summer.

Same area but from the beach view! My husband took this picture, one of my favorites!