Egg timer for staying awake all night long and not being run over by the Queen Mary

I have a regular kitchen timer but I sleep the sleep of the dead and it's innocuous sound does me no good to turn off and turn over to go back to sleep. So I went on the hunt for a real noise shattering device and found this.

Now this thing doesn't look like much but boy oh boy, does it demand respect! It starts out with some minuscule beeps and ends up with an ear piercing squawk, so if you don't get to it quickly, you will be sorry. So I have been practicing and last Saturday I went through the entire night waking up every hour for a little bit and then going back to sleep. I need to get it down to 20 minute intervals so I have a ways to go but it looks possible. The idea is that ships take around 20 minutes going at 15 knots from below the horizon to get to you. I plan on having AIS too which should alert them to my presence, but I would rather be proactive. Actually, the whole idea of a disturbed sleep really irritates me. I love my sleep almost as much as I like to eat and with the possible combination of seasickness and sleep deprivation, you have to wonder why on earth anyone would choose to go sailing.